• Title/Summary/Keyword: Weather feature

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A Study on the Air Traffic Situation Variables which Influence the Job Performance of Military Air Traffic Controllers (군관제사의 직무 수행과 항공교통상황 변인의 영향 연구)

  • Sin, Hyon-Sam;Jang, Jung-Ha;Ahn, Jae-Mo
    • Journal of the Korean Society for Aviation and Aeronautics
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    • v.20 no.1
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    • pp.19-25
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    • 2012
  • The air traffic situation variables were emphasized in this research to review the awareness level of job performance of military air traffic controllers in application of air traffic situation variables such as detection of aircraft identification, type of aircraft, position ,speed, altitude, determination of separation between departing and arriving in-trail aircraft, physical airport conditions, adverse weather conditions, NAVAID outage and ATC facilities' operational status. In this respect, This study was conducted under the auspice of ATC facility operating agencies and devoting air force air traffic controller's participation by answering the questionnaires from nine radar approach control facilities and other air traffic control towers.

TOVS retrieved data with the real time synoptic surface data (종관 지상 자료를 이용한 TOVS수치 해석 산출 자료)

  • 주상원;정효상;김금란
    • Korean Journal of Remote Sensing
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    • v.10 no.1
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    • pp.55-67
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    • 1994
  • The International TOVS(TIROS Oprational Vertical Sounders) Process Package(ITPP-VI)is for a global usage, which needs a surface data to generate atmospheric soundings. If the initial input process in the ITPP-VI is not modified, it takes climatic surface data for producing sounding data in general. Korea Meteorological Administration(KMA) is trying to improve the quality of TOVS sounding data using real-time synoptic observations and make a use weather prediction and analysis in various ways. Serval cases in this study show that TOVS retrieved meteolorogical parameters such as atmopheric temperature, dew point depression and geopotential heights used by synoptic surface observations can delineate more detailed atmospheric feature rather than those used by climate surface data. In addition, the collocated comparisons of TOVS synoptic retrieved parameters with radiosonde observations are performed statistically. TOVS retrieved fields with the synoptic surface analyzed data show smaller bias reatively than those with the climatic data and also reduced root mean square differences below 700 hPa as expected.

Consequence Analysis on the Leakage Accident of Hydrogen Fuel in a Combined Cycle Power Plant: Based on the Effect of Regional Environmental Features (복합화력발전소 내 수소연료 적용 시 누출 사고에 대한 피해영향범위 분석: 지역별 환경 특성 영향에 기반하여)

  • HEEKYUNG PARK;MINCHUL LEE
    • Transactions of the Korean hydrogen and new energy society
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    • v.34 no.6
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    • pp.698-711
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    • 2023
  • Consequence analysis using an ALOHA program is conducted to calculate the accidental impact ranges in the cases of hydrogen leakage, explosion, and jet fire in a hydrogen fueled combined cycle power plant. To evaluate the effect of weather conditions and topographic features on the damage range, ALOHA is executed for the power plants located in the inland and coastal regions. The damage range of hydrogen leaked in coastal areas is wider than that of inland areas in all risk factors. The obtained results are expected to be used when designing safety system and establishing safety plans.

A Study on Heavy Rainfall Guidance Realized with the Aid of Neuro-Fuzzy and SVR Algorithm Using AWS Data (AWS자료 기반 SVR과 뉴로-퍼지 알고리즘 구현 호우주의보 가이던스 연구)

  • Kim, Hyun-Myung;Oh, Sung-Kwun;Kim, Yong-Hyuk;Lee, Yong-Hee
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.63 no.4
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    • pp.526-533
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    • 2014
  • In this study, we introduce design methodology to develop a guidance for issuing heavy rainfall warning by using both RBFNNs(Radial basis function neural networks) and SVR(Support vector regression) model, and then carry out the comparative studies between two pattern classifiers. Individual classifiers are designed as architecture realized with the aid of optimization and pre-processing algorithm. Because the predictive performance of the existing heavy rainfall forecast system is commonly affected from diverse processing techniques of meteorological data, under-sampling method as the pre-processing method of input data is used, and also data discretization and feature extraction method for SVR and FCM clustering and PSO method for RBFNNs are exploited respectively. The observed data, AWS(Automatic weather wtation), supplied from KMA(korea meteorological administration), is used for training and testing of the proposed classifiers. The proposed classifiers offer the related information to issue a heavy rain warning in advance before 1 to 3 hours by using the selected meteorological data and the cumulated precipitation amount accumulated for 1 to 12 hours from AWS data. For performance evaluation of each classifier, ETS(Equitable Threat Score) method is used as standard verification method for predictive ability. Through the comparative studies of two classifiers, neuro-fuzzy method is effectively used for improved performance and to show stable predictive result of guidance to issue heavy rainfall warning.

Estimation and Prediction of the Heat Load Profile Using Weather and Heating/Cooling Data : An Application of the Multilevel Model (기상자료와 냉난방 실측자료를 이용한 열부하 추정과 예측: 다계층모형의 활용)

  • Moon, Choon-Geol;Kim, Suduk
    • Environmental and Resource Economics Review
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    • v.16 no.4
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    • pp.803-832
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    • 2007
  • Electricity and heat load profiles by use types on an hourly basis at the least are essential for assessing economic viability of new cogeneration and CES projects and for optimally operating existing cogeneration and CES facilities. We adopt a multilevel model to specify heat load profiles so as to utilize in a flexible manner the panel nature of our data on weather and heating/cooling use. Converting the multilevel model to the linear mixed-effects model, we estimate the model by panel FGLS. The estimated load profile model for each distinct use type accounts for the effects of temperature, humidity, each hour over the year, each day of the week, each type of legal holidays, and heating/cooling area on energy use. To save space, we feature in detail the heating profile of the household.

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The Effect of Replacement Ratio of Mineral Admixtures and Curing Condition on Compressive Strength of Hot Weather Concrete (혼화재 치환율 및 양생조건이 서중콘크리트의 압축강도에 미치는 영향)

  • Kong, Tae-Woong;Lee, Soo-Hyung;Jang, Jae-Hwan;Lee, Han-Baek
    • Proceedings of the Korea Concrete Institute Conference
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    • 2008.11a
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    • pp.629-632
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    • 2008
  • As concrete is a material which is subject to wide quality fluctuations by temperature, grip of seasonal feature and maintenance of ambient temperature and humidity to secure the quality required after casting concrete are able to keep away from harmful effects. In case of summer, a high temperature has caused rapid hydration reaction of cement in early age, which has caused to decrease strength by autogenous shrinkage. Therefore we need to consider a countermeasure for decrease in the hydration heat of hot-weather concrete, according to minimize water and cement content and use mineral admixtures In this experimental research, the compressive strength development for replacement ratio of mineral admixtures, curing temperature and methods of concrete was investigated to confirm the effects of mixture design and curing condition on compressive strength of concrete.

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Characterization of the Variability of Summer Extreme Precipitation According to the Local Features (지역특성에 따른 여름철 극한강수 변화특성 분석)

  • Kim, Gwangseob;Kim, Jong Pil
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.31 no.2B
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    • pp.129-146
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    • 2011
  • Characterization the regional impact of the variability of summer extreme precipitation and the rain days over several thresholds (i.e. 10, 20, 30, 40, 50, 60, 70 and 80 mm/day) in South Korea was performed using daily precipitation data of 59 weather stations operated by Korean Meteorological Administration (KMA). To consider the local features of weather stations, we characterized the variability according to the difference of elevations, latitudes, longitudes, river basins, inland or shore area, and the ratio of urbanization. The results showed that the summer extreme precipitation is sensible to the geographical effect which is similar to that of the annual precipitation. Rain days over thresholds have increased during 1973-2009 while the annual rain days have decreased. This indicate that the concentration of precipitation in summer season will be intensified in the future. Increase of summer precipitation amount and number of extreme rain days is higher in inland area, urbanized area, and Han-River basin than that of shore area, unurbanized area, and the other river basins respectively.

Verification of Precipitation Forecast Model and Application of Hydrology Model in Kyoungan-chun Basin (경안천 유역에 대한 강수예보모델의 검증 및 수문모형활용)

  • Choi, Ji-Hye;Kim, Young-Hwa;Nam, Kyung-Yeub;Oh, Sung-Nam
    • Journal of Korea Water Resources Association
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    • v.39 no.3 s.164
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    • pp.215-226
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    • 2006
  • In this study, we performed verification of VSRF (Very Short Range Forecast of precipitation) model and application of NWSPC (National Weather Service PC) rainfall-runoff model in Kyoungan-chun basin. We used two methods for verification of VSRF model. The first method is a meteorological verification that evaluates the special quality feature for rain amount between AWS and VSRF model over Kyoungan-chun basin, while second method is a hydrological verification that compares the calculated Mean Area Precipitation (MAP) between AWS and VSRF Quantitatively. This study examines the usefulness of VSRF precipitation forecasting model data in NWSPC hydrological model. As a result, correlation coefficient is over 0.6 within 3 hour lead time. It represents that the forecast results from VSRF are useful for water resources application.

Heojun's Outlook on Nature (허준(許浚)의 자연관(自然觀) - 『동의보감(東醫寶鑑)』을 중심으로 -)

  • Park, Seong-Kue;Kim, Sue Joong;Kim, Nam Il
    • The Journal of Korean Medical History
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    • v.18 no.2
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    • pp.197-227
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    • 2005
  • Heojun was the top scientist on Medicine in the 16th and 17th centuries and wrote the Dongeubogam describing the top-level medical theory and technology. So far, his outlook on nature has been disregarded even though his medicine is still effective. Through this study, I would like to know if his outlook on nature as well as his medicine is still effective. The conclusions are as follows: 1. According to his output, the origin of the universe started from the spinning of One Gi(一氣) which is quite different from Hawking's theory. Hawking assumed that the origin of the universe started from the Big-bang and will end to the Big-crunch. However, the current report on the origin of a star is quite similar to Heojun's theory and we acknowledge that his view on the origin of the universe is still effective. 2. According to his output, the universe repeats expanding and contracting forever while Hawking assumed it will come to the end, the Big-crunch, based on the expanding universe theory. Some scientists assists that Hawking's assumption should have some contradictions. Now, we acknowledge that Heojun's universal cycling theory which corresponds with modern physical theories is still effective, which would lead to a new environmental movement. 3. His view on the structure of the universe is quite different from the output of the current science, which results from his thought that the nature should be reviewed from the point of human's view. His view on the structure will be able to be updated based on the output of the current science. 4. The universe analogy started from the East Asian area as well as the Greek and Roman area in the ancient. The idea has disappeared since the scientific revolution era in the West while the idea has been deepened and abundant in the East and has become one of the major philosophical bases. Heojun emphasized its importance from the beginning of his book. 5. The nation analogy has been popular all times and places. According to his output, governing a country is like controlling one's body. 6. According to Needham's output, the universe analogy and the nation analogy were based on the ancient developed alchemy. And Harper assumed that Taiosm was based on the macrobiotic hygiene which was developed by the ancient developed alchemists. We acknowledge that xian(仙) cult, macrobiotic hygiene, medicine, alchemy and the ancient philosophy started from our ancients. Heojun's output restored our ancient tradition by combining the macrobiotic hygiene and philosophy with medicine. 7. Roughly predicting yearly weather would be unacceptable by the current scientist but Heojun's yearly weather forecast is still used in the clinic and seems effective to prepare from any epidemic disease. 8. 'Day and Night' and Four seasons are the most important factors to the macrobiotic hygiene according to the Dongeubogam. The new environmental movements should be based on the most important factors, otherwise the human beings as well as the environment would fail to survive. 9. Wind, Coldness, Heat, Humidity, Dryness and Fire represents weather. The six weather factors represent one of six phases of a year which is decided by the areal factors. Heojun preferred the six factors generated in the body itself to them from the outside. He thought a human being was a universe and the six factors generated in the body responded to the factors of the outside. 10. According to his output, Heat and Humidity are the most important factors which make a human being ill. 11. Life span, disease, food, and dwelling are dependent upon the geographical feature, according to Heojun's output. In addition, one's appearance and his five viscera and the six entrails depend on the food as well as the geographical feature. 12. Heath is related with the environment and they effects upon each other. If one is weak, he will be deeply effected by the nature. On the other hand, if one is strong, he will effect on the nature. That's why people live together. 13. According to Heojun's work, the society is an important factor comprising the environment. During a peaceful era, the society becomes stable and human beings are stable as well while they will be on fire during a chaotic era. 14. Medicine deals with human beings who live in the nature, so any medical book cannot be excellent unless it has any description on the nature. Heojun's outlook on the nature turned out to be logical and suitable even from the point of the current view and it is still effective as if his clinical knowledge and technology are still effective. Something unsuitable may be substituted with the output of the current science.

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Predicting Determinants of Seoul-Bike Data Using Optimized Gradient-Boost (최적화된 Gradient-Boost를 사용한 서울 자전거 데이터의 결정 요인 예측)

  • Kim, Chayoung;Kim, Yoon
    • The Journal of the Convergence on Culture Technology
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    • v.8 no.6
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    • pp.861-866
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    • 2022
  • Seoul introduced the shared bicycle system, "Seoul Public Bike" in 2015 to help reduce traffic volume and air pollution. Hence, to solve various problems according to the supply and demand of the shared bicycle system, "Seoul Public Bike," several studies are being conducted. Most of the research is a strategic "Bicycle Rearrangement" in regard to the imbalance between supply and demand. Moreover, most of these studies predict demand by grouping features such as weather or season. In previous studies, demand was predicted by time-series-analysis. However, recently, studies that predict demand using deep learning or machine learning are emerging. In this paper, we can show that demand prediction can be made a little better by discovering new features or ordering the importance of various features based on well-known feature-patterns. In this study, by ordering the selection of new features or the importance of the features, a better coefficient of determination can be obtained even if the well-known deep learning or machine learning or time-series-analysis is exploited as it is. Therefore, we could be a better one for demand prediction.