• Title/Summary/Keyword: Cloud-cover

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Characteristics of Air Pollution at Kimhae (김해지방의 대기오염 특성)

  • 박종길;김종필;김지형
    • Journal of Environmental Science International
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    • v.8 no.1
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    • pp.33-43
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    • 1999
  • This paper aims to describe the characteristics of air pollution using air pollutants concentration and meteorological data observed at Kimhae from December 1996 to November, 1997. The results are as follows : The concentration distribution of sulfur dioxide($SO_2$), carbon monoxide(CO), particulate matter(PM-10), and nitrogen dioxide($NO_2$) is high during the late fall and winter and low during the summer, but ozone concentration is low during the winter season and high during summer season except Jangma period and these distributions appear to be closely connected with insolation and the number of clear day. Diurnal variation of concentrations for sulfur dioxide, particulate matter, and carbon monoxide are high during the rush hours and nighttime and low during the daytime and these variations are distinct toward the winter season. And diurnal variation of nitrogen dioxide concentration has also same pattern and these patterns are closely related to the increasing traffic volume at rush hours. Diurnal variation of ozone concentration is generally increase for daytime and decrease for the late afternoon and are closely related to the insolation and photochemical reaction. The 24 hour average concentrations of air pollutant observed at Kimhae represented a positive correlation and a negative correlation for $O_3$ and also a negative correlation for the meteorological elements such as wind speed and cloud cover.

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A Study the Costume of Kublai Khan of the Kublai Khan on a Hunting Trip (원세조출엽도 중의 세조 복식 연구)

  • Koh Bou-Ja;Choi Kyu-Soon
    • The Research Journal of the Costume Culture
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    • v.13 no.4 s.57
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    • pp.658-670
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    • 2005
  • Kublai Khan on a Hunting Trip were painted by Liu Guan-dao. This painting gives us very important information for understanding cosume of Yuan dynasty because of realistic description. We studied the name of costume of the king Shizu in this painting by using the way of comparison his costume with another paintings, the records and archaeological finds. This study showed that the costume of the king Shizu is judged to be Jisun, the traditional costume of Mongolian own meaning one colour. The name of each is the Yinshu warm hat, being making into the for of a kind of rodents, the Yinshu Jisun, the Red colour Jisun, being railed on the robe, and the Cloud boots cover. And we found that the decoration on the neck and sleeve tib of the Yinshu Jisun had been made by sable furs, and the decoration on the surface had been made by tails of them, going by the name of Rondes at that time. It also showed that the meaning of one colour of the Jisun is not only just appearing one colour on the one person but also being able to appear two set of one colour.

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Auto Configuration Module for Logstash in Elasticsearch Ecosystem

  • Ahmed, Hammad;Park, Yoosang;Choi, Jongsun;Choi, Jaeyoung
    • Annual Conference of KIPS
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    • 2018.10a
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    • pp.39-42
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    • 2018
  • Log analysis and monitoring have a significant importance in most of the systems. Log management has core importance in applications like distributed applications, cloud based applications, and applications designed for big data. These applications produce a large number of log files which contain essential information. This information can be used for log analytics to understand the relevant patterns from varying log data. However, they need some tools for the purpose of parsing, storing, and visualizing log informations. "Elasticsearch, Logstash, and Kibana"(ELK Stack) is one of the most popular analyzing tools for log management. For the ingestion of log files configuration files have a key importance, as they cover all the services needed to input, process, and output the log files. However, creating configuration files is sometimes very complicated and time consuming in many applications as it requires domain expertise and manual creation. In this paper, an auto configuration module for Logstash is proposed which aims to auto generate the configuration files for Logstash. The primary purpose of this paper is to provide a mechanism, which can be used to auto generate the configuration files for corresponding log files in less time. The proposed module aims to provide an overall efficiency in the log management system.

A Study on the Estimating Solar Radiation by Empirical Regression Models (경험적인 회귀모델에 의한 일사예측에 관한 연구)

  • Jo, Dok-Ki;Kim, Eun-Ill;Lee, Tae-Kyu;Chun, Il-Soo;Jeon, Hong-Seok;Auh, Chung-Moo
    • Solar Energy
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    • v.14 no.2
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    • pp.17-28
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    • 1994
  • It is necessary to estimate enpirical constants in order to predict the monthly mean daily global radiation on a horizontal surface in the developing areas for alternative energy. Therefore many different equations have propoed to evaluate them for certain areas. In this work a new corrlation has been made to predict the solar radiation for any areas over Korea by cululating the regression models taking into account latitude, percentage of possible sunshine, and cloud cover. From the results, the single linear equation proposed by using percentage of possible sunshine method shows reliable results for estimating the global rdiation with average annual deviation of -4 to +2% from measured values.

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A Study on Managing Dataset Records in Government Information Systems (행정정보 데이터세트 기록의 관리방안)

  • Wang, Ho-sung;Seol, Moon-won
    • Journal of Korean Society of Archives and Records Management
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    • v.17 no.3
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    • pp.23-47
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    • 2017
  • According to a recent survey, over 18,000 government information systems have numerous different functions and characteristics. Although every dataset that is created and maintained in government information systems is declared as a collection of records according to the Public Records Management Act, current electronic records management policies cannot cover dataset records management. This study suggests the policy directions for dataset records management at the national level. It emphasizes the necessity to preserve the appearance and behavior (function) of database systems to ensure the authenticity of dataset records. In addition, this study investigates "emulation" as a representation and long-term preservation methodology for dataset-type records. It also suggests a dataset records model.

Beam and Diffuse to Global Solar Irradiation Correlation Coefficients for Daejeon (대전지역 직달 및 산란과 전일사 상관계수)

  • Lee, Kwan-Ho;Song, Doo-Sam
    • Journal of the Korean Solar Energy Society
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    • v.39 no.4
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    • pp.11-24
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    • 2019
  • The total solar irradiation on horizontal surfaces is separated into the beam and diffuses components. Although horizontal global irradiance is a commonly measured parameter for many sites, horizontal diffuse irradiance is not so readily obtainable. For such sites that measure global irradiation alone, a simple but reasonably accurate method is required to estimate diffuse irradiance from its global counterpart. This study investigates the applicability of correlation coefficients models correlating hourly diffuse and beam fraction and hourly clearness index in Daejeon. The three diffuse to global correlation coefficients models (Orgill and Holland model, CIBSE Guide J model, and Erbs et al. model) are selected and the three modified beam to global correlation coefficients models are generated. MBE, RMSE, r-squared of Daejeon and Daejeon boundary site-fitted models are compared with the case of original coefficients. The comparison result shows that the beam and diffuse to global solar irradiation correlation coefficients models with boundary site-fitted coefficients are best suitable for Daejeon. Further researches will be conducted to find the boundary site-fitting method using measured data of other cities and correlation coefficients models using solar altitude, cloud cover, and sunshine duration.

A Research of Prediction of Photovoltaic Power using SARIMA Model (SARIMA 모델을 이용한 태양광 발전량 예측연구)

  • Jeong, Ha-Young;Hong, Seok-Hoon;Jeon, Jae-Sung;Lim, Su-Chang;Kim, Jong-Chan;Park, Hyung-Wook;Park, Chul-Young
    • Journal of Korea Multimedia Society
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    • v.25 no.1
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    • pp.82-91
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    • 2022
  • In this paper, time series prediction method of photovoltaic power is introduced using seasonal autoregressive integrated moving average (SARIMA). In order to obtain the best fitting model by a time series method in the absence of an environmental sensor, this research was used data below 50% of cloud cover. Three samples were extracted by time intervals from the raw data. After that, the best fitting models were derived from mean absolute percentage error (MAPE) with the minimum akaike information criterion (AIC) or beysian information criterion (BIC). They are SARIMA (1,0,0)(0,2,2)14, SARIMA (1,0,0)(0,2,2)28, SARIMA (2,0,3)(1,2,2)55. Generally parameter of model derived from BIC was lower than AIC. SARIMA (2,0,3)(1,2,2)55, unlike other models, was drawn by AIC. And the performance of models obtained by SARIMA was compared. MAPE value was affected by the seasonal period of the sample. It is estimated that long seasonal period samples include atmosphere irregularity. Consequently using 1 hour or 30 minutes interval sample is able to be helpful for prediction accuracy improvement.

Record-breaking High Temperature in July 2021 over East Sea and Possible Mechanism (2021년 7월 동해에서 발생한 극한 고온현상과 기작)

  • Lee, Kang-Jin;Kwon, MinHo;Kang, Hyoun-Woo
    • Atmosphere
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    • v.32 no.1
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    • pp.17-25
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    • 2022
  • As climate change due to global warming continues to be accelerated, various extreme events become more intense, more likely to occur and longer-lasting on a much larger scale. Recent studies show that global warming acts as the primary driver of extreme events and that heat-related extreme events should be attributed to anthropogenic global warming. Among them, both terrestrial and marine heat waves are great concerns for human beings as well as ecosystems. Taking place around the world, one of those events appeared over East Sea in July 2021 with record-breaking high temperature. Meanwhile, climate condition around East Sea was favorable for anomalous warming with less total cloud cover, more incoming solar radiation, and shorter period of Changma rainfall. According to the results of wave activity flux analysis, highly activated meridional mode of teleconnection that links western North Pacific to East Asia caused localized warming over East Sea to become stronger.

Assessing the Impact of Long-Term Climate Variability on Solar Power Generation through Climate Data Analysis (기후 자료 분석을 통한 장기 기후변동성이 태양광 발전량에 미치는 영향 연구)

  • Chang Ki Kim;Hyun-Goo Kim;Jin-Young Kim
    • New & Renewable Energy
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    • v.19 no.4
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    • pp.98-107
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    • 2023
  • A study was conducted to analyze data from 1981 to 2020 for understanding the impact of climate on solar energy generation. A significant increase of 104.6 kWhm-2 was observed in the annual cumulative solar radiation over this period. Notably, the distribution of solar radiation shifted, with the solar radiation in Busan rising from the seventh place in 1981 to the second place in 2020 in South Korea. This study also examined the correlation between long-term temperature trends and solar radiation. Areas with the highest solar radiation in 2020, such as Busan, Gwangju, Daegu, and Jinju, exhibited strong positive correlations, suggesting that increased solar radiation contributed to higher temperatures. Conversely, regions like Seosan and Mokpo showed lower temperature increases due to factors such as reduced cloud cover. To evaluate the impact on solar energy production, simulations were conducted using climate data from both years. The results revealed that relying solely on historical data for solar energy predictions could lead to overestimations in some areas, including Seosan or Jinju, and underestimations in others such as Busan. Hence, considering long-term climate variability is vital for accurate solar energy forecasting and ensuring the economic feasibility of solar projects.

A Study on the Retrievals of Downward Solar Radiation at the Surface based on the Observations from Multiple Geostationary Satellites (정지궤도 위성자료를 이용한 지표면 도달 태양복사량 연구)

  • Jee, Joon-Bum;Zo, Il-Sung;Lee, Kyu-Tae
    • Korean Journal of Remote Sensing
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    • v.29 no.1
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    • pp.123-135
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    • 2013
  • The reflectance observed in the visible channels of a geostationary meteorological satellite can be used to calculate the amount of cloud by comparing the reflectance with the observed solar radiation data at the ground. Using this, the solar radiation arriving at the surface can be estimated. This study used the Meteorological Imager (MI) reflectance observed at a wavelength of 675 nm and the Geostationary Ocean Color Imager (GOCI) reflectance observed at similar wavelengths of 660 and 680 nm. Cloudy days during a typhoon and sunny days with little cloud cover were compared using observation data from the geostationary satellite. Pixels that had more than 40% reflectance in the satellite images showed less than 0.3 of the cloud index and blocked more than 70% of the solar energy. Pixels that showed less than 15% reflectance showed more than 0.9 of the cloud index and let through more than 90% of the solar energy to the surface. The calculated daily accumulated solar radiation was compared with the observed daily accumulated solar radiation in 22 observatories of the Korean Meteorological Administration. The values calculated for the COMS and MTSAT MI sensors were smaller than the observation and showed low correlations of 0.94 and 0.93, respectively, which were smaller than the 0.96 correlation coefficient calculated for the GOCI sensor. The RMSEs of MTSAT, COMS MI and GOCI calculation results showed 2.21, 2.09, 2.02 MJ/$m^2$ in order. Comparison of the calculated daily accumulated results from the GOCI sensor with the observed data on the ground gave correlations and RMSEs for cloudy and sunny days of 0.96 and 0.86, and 1.82 MJ/$m^2$ and 2.27 MJ/$m^2$, respectively, indicating a slightly higher correlation for cloudy days. Compared to the meteorological imager, the geostationary ocean color imager in the COMS satellite has limited observation time and observation is not continuous. However, it has the advantage of providing high resolution so that it too can be useful for solar energy analysis.