• Title/Summary/Keyword: Weather elements

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A Study of Missile Guidance Performance Enhancement using Multi-sensor Data Fusion in a Cluttered Environment (클러터 환경에서 다중센서 정보융합을 통한 유도성능 개선 연구)

  • Han, Du-Hee;Kim, Hyoung-Won;Song, Taek-Lyul
    • Journal of Institute of Control, Robotics and Systems
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    • v.16 no.2
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    • pp.177-187
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    • 2010
  • A MTG (Multimode Tracking and Guidance) system is employed to compensate for the limitations of individual seekers such as RF (Radio frequency) or IIR (Imaging Infra-red) and to improve the overall tracking and guidance performance in jamming, clutter, and adverse weather environments. In the MTG system, tracking filter, data association, and data fusion methods are important elements to maximize the effectiveness of precision homing missile guidance. This paper proposes the formulation of a Kalman filter for the estimation of line-of-sight rate from seeker measurements in missiles guided by proportional navigation. Also, we suggest the HPDA (Highest Probability Data Association) and data fusion methods of the MTG system for target tracking in the adverse environments. Mont-Carlo simulation is employed to evaluate the overall tracking performance and guidance accuracy.

A STUDY ON THE ASTRONOMICAL OBSERVATIONAL ENVIRONMENTS AT THE CHOEJUNG-SAN GEODSS SITE: II. METEOROLOGICAL STUDY (최정산 위성추적소의 천체관측 환경에 관한 조사 연구: II. 천문 관측환경에 대한 기상학적 연구)

  • Yun, Il-Hui;An, Byeong-Ho;Kang, Yong-Hui;Yun, Tae-Seok
    • Publications of The Korean Astronomical Society
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    • v.11 no.1
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    • pp.197-220
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    • 1996
  • The climatological characteristics at the Choejung-san site were statistically analyzed using monthly normals for the various meteorological elements at Taegu meteorological station for 30 years from January 1960 to December 1990. Various synoptic weather conditions were classified by the estimated geostrophic wind speeds and direction determined using the 850 hPa geopotential height field for 10 years from December 1980 to November 1989. Also the analysis of number of clear days were monthly and seasonally performed using the satellite infrared image data which were obtained from GMS 5 for 5 years from December 1990 to November 1995. The results reveal that the meteorological environments of astronomical observation at Choejung-san site were very good conditions during three hours after midnight except for summer season.

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A Study on the Analysis of Lightning Damage Impact in Domestic Offshore Wind Farm (국내 해상풍력발전단지 낙뢰피해 영향 분석에 관한 연구)

  • Seo, Jin-Gyu;Kim, Kyu-Ho
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.65 no.2
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    • pp.247-252
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    • 2016
  • The latest offshore wind turbines are easily exposed to lightning strikes because they are designed with longer blades and taller height to satisfy the growing capacity demands. The generation facilities and elements of the offshore wind farm are more vulnerable to lightning damage because of more severe, unpredictable weather conditions. Therefore, this paper presents the analysis of measure for lightning overvoltage mitigation in offshore wind farm planned in South Korea southwest seashore. The sensitivity analysis includes the steady state and transient state characteristics of offshore wind farm and proposes the countermeasure for mitigation of transient overvoltage by considering earth resistivity of the offshore environment.

A Fuzzy Spatiotemporal Data Model and Dynamic Query Operations

  • Nhan, Vu Thi Hong;Kim, Sang-Ho;Ryu, Keun-Ho
    • Proceedings of the KSRS Conference
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    • 2003.11a
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    • pp.564-566
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    • 2003
  • There are no immutable phenomena in reality. A lot of applications are dealing with data characterized by spatial and temporal and/or uncertain features. Currently, there has no any data model accommodating enough those three elements of spatial objects to directly use in application systems. For such reasons, we introduce a fuzzy spatio -temporal data model (FSTDM) and a method of integrating temporal and fuzzy spatial operators in a unified manner to create fuzzy spatio -temporal (FST) operators. With these operators, complex query expression will become concise. Our research is feasible to apply to the management systems and query processor of natural resource data, weather information, graphic information, and so on.

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A Generation and Accuracy Evaluation of Common Metadata Prediction Model Using Public Bicycle Data and Imputation Method

  • Kim, Jong-Chan;Jung, Se-Hoon
    • Journal of Korea Multimedia Society
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    • v.25 no.2
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    • pp.287-296
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    • 2022
  • Today, air pollution is becoming a severe issue worldwide and various policies are being implemented to solve environmental pollution. In major cities, public bicycles are installed and operated to reduce pollution and solve transportation problems, and operational information is collected in real time. However, research using public bicycle operation information data has not been processed. This study uses the daily weather data of Korea Meteorological Agency and real-time air pollution data of Korea Environment Corporation to predict the amount of daily rental bicycles. Cross- validation, principal component analysis and multiple regression analysis were used to determine the independent variables of the predictive model. Then, the study selected the elements that satisfy the significance level, constructed a model, predicted the amount of daily rental bicycles, and measured the accuracy.

${\ll}$소문(素問).천원기대론(天元紀大論)${\gg}$ 에 대한 연구(硏究)

  • Park Gyeong;Geum Gyeong-Su;Kim Nam-Su;Yuk Sang-Won
    • Journal of Korean Medical classics
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    • v.13 no.1
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    • pp.102-116
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    • 2000
  • In Cheon Won Gi Dae Ron(天元紀大論), Cheon(大) means Nature, Won(元) means sources, Gi(紀) is Gang Gi(綱紀) that means rules or regulations, so Cheon Won Gi(天元紀) means sources and rules of change that make Nature phenomenons. This volume treats of cause that weather change of Nature caused by, and its general rules, and presents fundamental notions and systems of measuring of 'Five elements' evolutions and Six kinds of natural factors(五運六氣)'. So named Cheon Won Gi Dae Ron(天元紀大論). This article of the research on the Cheon Won Gi Dae Ron(天元紀大論) can be divided into 3 chapters. Chapter 1 presents a theory that the principle of changes of creations' birth, groth and extinction is complished by sympathizing with Hyeong(形) of Ji(地) and Gi(氣) of Cheon(大) by rules of movement of O Un Yum Yang(五運陰陽). Chapter 2 presents theories that Tae Heo(太虛) makes Won Gi(元氣), and this Won Gi(元氣) makes the change of creations' birth, groth and extinction, and movement of O Un(五運) controls creation of nature. And treats of that 'excessive and short(太過不及)' that is made by a quality of Gi(氣) and ups and dons of Hyeong(形) controls weather of year. In Chapter 3, Cheon O Ji Yuk(天五地六) regard six and five as Yong(用). And A Cycle that movment that sympathizing with O Un(五運) and Yuk Gi(六氣) is Il Gi(一氣) as 30 years, and Il Ju(一周) as 60 years. And presents that O Un(五運) and Yuk Gi(六氣) that Gan Ji(干支) control.

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On the Characteristics of Vertical Atmospheric Structure in the Western Coastal Region through the Intensive Observation Period (집중관측을 통한 서해연안의 대기 수직구조 특성)

  • 문승의;노재식
    • Journal of Environmental Science International
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    • v.7 no.3
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    • pp.335-348
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    • 1998
  • The intensive meteorological observations including pibal balloon at Ungcheon, airsonde and 10m meteorological tower observations at Gulup-Do, where are located In the western coastal region, are taken to Investigate the characteristics of the upper and lower atmospheric structure and the local circulation pattern during the period of 17 to 22 September 1996. The diurnal variations of weather elements(i.e. air temperature, humidity, pressure, and Und speeds at Gulup-Do are analyzed and discussed with those at four inland meteorological stations. The vertical profiles of wind vector, ortho- gonality(Ω), and shear obtained from the pibal obsenrations are also presented to examine the change of wand structure according to the synoptic-scale pressure system's movement. The diurnal temperature changes at Gulup-Do are more sensitive than that of Inland meteorological stations In case of the mow of southwesterlies but are not dominant due to the ocean effect under the Influence of relatively cold northerlies. A well defined mixed layer Is developed from the 500m to the maximum 1700m with a significant capping Inversion layer on the top of it. It can be found from the vertical profiles of wind vector that the wind become generally strong at the interface heights between cloud lay- ers and non-cloud layers. The maximum Und shear Is appeared at the bel각t where the varlauon of wand direction Induced by the passage of synoptic-scale pressure system Is accompanied with the In- crease of Und speed. Based on the wind orthogonality, the change of wind direction with height is more complicated In cloudy day than In clear day. In case of a fair weather, the change of wand direction is showed to be at around 2km.

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Comparative Analysis of Anion Concentration by the Type of Roadside Buffer Green (가로변 완충녹지의 조성유형에 따른 음이온 농도 비교 분석)

  • Yoon, Yong-Han;Joo, Chang-Hun;Park, Hun;Kim, Jeong-Ho
    • Journal of Environmental Science International
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    • v.23 no.7
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    • pp.1339-1347
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    • 2014
  • This study were performed on roadside buffer green in Songpa-dong, Songpa-gu, Seoul in order to analyze the anion concentration according to the type of composition of roadside buffer green. Buffer green separating the physical structure of the measurement points and measurement locations were separated by roadside, green interior, the other side of the road. planting density and deposit of trees per each buffer green was measured in the order of mounding type> slope type> the plain type. If the measured temperature of the location-specific weather elements roadside> inside> the other side of the road in order of measurement and the temperature is lowered farther away from the road. If the relative humidity of the road on the other side> inside> the roadside in order to measure and this is the opposite of the temperature tendency. According to physical structure reduction of the temperature on the other side of the road and roadside in order of mounding type> the plain type> slope type was measured. As a result of measuring a anion therefore concentration of the anion inside of melt is in order of mounding type> the plain type> slope type, tended to match the melt characteristics. According to measured positions anion concentration is in the order of the other side of the road> inside> the roadside was measured. As a result of correlation analysis, in the case of measurement location-specific weather and anions the temperature is positive correlation, relative humidity is negative correlation and that's results of previous studies were supported.

Data Mining of Gas Accident and Meteorological Data in Korea for a Prediction Model of Gas Accidents (국내 가스사고와 기상자료의 데이터마이닝을 이용한 가스사고 예측모델 연구)

  • Hur, Young-Taeg;Shin, Dong-Il;Lee, Su-Kyung
    • Journal of the Korean Institute of Gas
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    • v.16 no.1
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    • pp.33-38
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    • 2012
  • Analysis on gas accidents by types occurred has been made to prevent the recurrence of accidents, through analysis of past history of gas accident occurring environment. The number of gas accidents has been decreasing, but still accidents are occurring steadily. Gas-using environment and gas accidents are estimated to be closely connected since gas-using types are changing by time period, weather, etc. in terms of accident contents. As a result of analysing gas accidents by 7 meteorological elements, such as the mean temperature, the highest temperature, the lowest temperature, relative humidity, the amount of clouds, precipitation and wind velocity, it has been found out that gas accidents are influenced by temperature or relative humidity, and accident occurs more frequently when the sky is clean and wind velocity is slow. Possibility of gas accidents can be provided in real time, using the proposed model made to predict gas accidents in connection with the weather forecast service. Possibility and number of gas accidents will be checked real time by connecting to the business system of Korea Gas Safety Corp., and it is considered that it would be positively used for preventing gas accidents.

The Effect of Built Environment on Walkability in Ho Chi Minh City Center District (건축 환경이 호치민시 보행편의성에 미치는 영향)

  • Loc, Duong Quy;Kim, Gyeng-Seok
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.19 no.9
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    • pp.288-297
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    • 2018
  • Walking plays an important role in promoting peoples' health and reducing the increasing pressure of traffic congestion. However, for cities in developing countries located in areas with unfavorable weather, such as hot and humid weather, there is not much research on walking. Therefore, this study focuses on the walkability and the effect of the built environment on walking in the center district of Ho Chi Minh City, Vietnam. The correlation between the built environment and walking frequency of people was analyzed. Besides common elements that have been used in previous studies, other specific factors of the built environment were determined to estimate the walkability index. The results were then compared with the amount of walking obtained from surveys of local people. The result shows that people tend to walk more in the areas with a higher walkability index.