• Title/Summary/Keyword: weather parameters

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Quality Analysis of SAR Image

  • Lee, Young-Ran;Kwak, Sung-Hee;Shin, Dong-Seok;Park, Won-Kyu
    • Proceedings of the KSRS Conference
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    • 2003.11a
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    • pp.628-630
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    • 2003
  • Synthetic Aperture Radar(SAR) is an active microwave instrument that performs high-resolution observation under almost all weather condition. Research and algorithms have been proposed to process radar signal and to increase the quality of SAR products. In fact, many complicated steps are involved in order to generate a SAR image product. The purpose of this paper is to derive quality assessment procedures and define important test parameters in each procedure inside a SAR processor. Thus those test parameter values indicate the quality of SAR image products and verify the processor's performance. Moreover, required procedures to correct and handle errors which are indicated during the assessment are also presented.

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Analysis of the lightning characteristics by the LPATS in KOREA (낙뢰위치 표정시스템(LPATS)에 의한 2004넌 한반도 낙뢰통계 분석결과)

  • Kwak, J.S.;Woo, J.W.;Kweon, D.J.;Kang, Y.W.;Moon, J.D.
    • Proceedings of the KIEE Conference
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    • 2005.07a
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    • pp.606-608
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    • 2005
  • As the overhead transmission lines are exposed to the outdoor weather, the causes of the transmission lines faults are from natural conditions, and among these faults, the outage rate due to lightning is more than 60%. The lightning causes the damage of power system equipments, the shut down of electricity and the electro-magnetic interference. Therefore, the pertinent insulation design is important, not only to decrease the damage of the facility itself but also to increase the reliability of electric power system. For these reasons, we have to obtain and accumulate the lightning current parameters for the basic lightning research. This paper describes the statistical distribution of lightning current parameters and the IKL map.

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Analysis of the lightning characteristics by the Lightning DB in KOREA (낙뢰위치표정시스템의 낙뢰 DB를 이용한 한반도 뇌격 특이특성 분석)

  • Woo, J.W.;Kwak, J.S.;Shim, E.B.;Lee, G.W.;Kim, K.W.;Kim, B.S.
    • Proceedings of the KIEE Conference
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    • 2001.07c
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    • pp.1658-1660
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    • 2001
  • Because the overhead transmission lines are exposed to the outdoor weather, the faults of the transmission lines are due to natural conditions, and among these faults, the outage rate by lightning is about 50%. The lightning causes the damage of power system equipments, the shut down of electricity and the electro-magnetic interference. Therefore, the pertinent insulation design is important, not only to decrease the damage of the facility itself but also to increase the reliability of electric power system. For these reasons, we have to obtain and accumulate the lightning current parameters for the basic lightning research. This paper describes the statistical distribution of lightning current parameters and the IKL map.

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Wind energy assessment at complex terrain using mixture probability distribution (혼합확률분포를 이용한 복잡지형의 풍력자원 평가)

  • Song, Ho-Sung;Kwon, Soon-Duck
    • Journal of the Korean Solar Energy Society
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    • v.33 no.2
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    • pp.18-27
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    • 2013
  • This paper presents a method for assessing the wind energy potential at complex terrain using probability distribution. And the proper probability models of the parameters estimating the wind energy are presented. Finally a mixture-Weibull determined by numerical methods procedure are proposed to assess the probability distribution of the energy potential at a site. The developed method is applied to the Kwanjungchun Bridge and compared with wind records which the neighboring weather station.

Optimized Station to Estimate Atmospheric Integrated Water Vapor Levels Using GNSS Signals and Meteorology Parameters

  • Beldjilali, Bilal;Benadda, Belkacem
    • ETRI Journal
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    • v.38 no.6
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    • pp.1172-1178
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    • 2016
  • The atmospheric meteorology parameters of the earth, such as temperature, pressure, and humidity, strongly influence the propagation of signals in Global Navigation Satellite Systems (GNSSs). The propagation delays associated with GNSS signals can be modeled and explained based on the atmospheric temperature, pressure, and humidity, as well as the locations of the satellites and receivers. In this paper, we propose an optimized and simplified low cost GNSS base weather station that can be used to provide a global estimate of the integrated water vapor value. Our algorithm can be used to measure the zenith tropospheric delay based on the measured propagation delays in the received signals. We also present the results of the data measurements performed at our station located in the Tlemcen region of Algeria.

Analysis of the lightning characteristics by LPATS Data during 7 year (LPATS에 의한 7년간의 한반도 뇌격특성분석)

  • Woo, J.W.;Shim, E.B.;Kwak, J.S.;Kweon, D.J.;Moon, J.D.;Han, S.O.
    • Proceedings of the KIEE Conference
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    • 2003.07a
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    • pp.509-511
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    • 2003
  • Because the overhead transmission lines are exposed to the outdoor weather, the faults of the transmission lines are due to natural conditions, and among these faults, the outage rate by lightning is about 50%. The lightning causes the damage of power system equipments, the shut down of electricity and the electro-magnetic interference. Therefore, the pertinent insulation design is important, not only to decrease the damage of the facility itself but also to increase the reliability of electric power system. For these reasons, we have to obtain and accumulate the lightning current parameters for the basic lightning research. This paper describes the statistical distribution of lightning current parameters and the IKL map.

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Application of Dynamic Model SIMRIW for Predicting the Growth and Yield of Rice (수도성장 및 수량예측을 위한 동적모형 SIMRIW의 적용)

  • 이남호
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.35 no.2
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    • pp.73-80
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    • 1993
  • A simplified physiologically-based dynamic model, SIMRIW was selected for predicting the growth and yield of rice. The applicability of the model to the rice cultivars and weather conditions in the Republic of Korea was evaluated. Parameters of the model were calibrated using actual rice yields in Suweon region and an optimization scheme, Constrained Rosenbrock Algorithm. The simulated results from the calibrated model were in good agreement with the field data. The model with parameters calibrated for Suweon was applied to other five regions for the evaluation of transferability, but the simulated results fell short of satisfaction. However, the model is found to be applied to real-time prediction of the growth and yield of rice crop, which is believed to be useful for timely rice crop management, agricultural policy making, and optimal irrigation water management.

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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.

Study on Thermal Performance Characteristics of CPC System Depending on Weather Conditions and Capacity of Heat Storage Tank (기상 조건과 축열조 용량에 따른 복합 포물형 집열기(CPC) 시스템의 열적 성능 특성에 관한 연구)

  • LIM, SOK-KYU;JUNG, YOUNG GUAN;KIM, KYOUNG HOON
    • Transactions of the Korean hydrogen and new energy society
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    • v.30 no.1
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    • pp.58-66
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    • 2019
  • Static compound parabolic collectors (CPCs) have advantages such as ease for fabrication and lower cost compared with other concentrating collectors. In this study, thermal performance analysis of CPC employing heat storage tank was carried out. The clearness index and capacity of heat storage tank are taken as the main parameters for numerical simulation. The effects of the parameters on the hourly and daily system performances ncluding the useful energy, heat loss, and collector efficiency were numerically investigated. Results showed that the system has a potential for efficient recovery of solar thermal energy.

Influence of HAPS and GEO Satellite under SANDU Layering and Gas Attenuations

  • Harb, Kamal
    • International Journal of Computer Science & Network Security
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    • v.21 no.12
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    • pp.93-100
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    • 2021
  • Satellite communication for high altitude platform stations (HAPS) and geostationary orbit (GEO) systems suffers from sand and dust (SANDU) storms in desert and arid regions. The focus of this paper is to propose common relations between HAPS and GEO for the atmospheric impairments affecting the satellite communication networks operating above Ku-band crossing the propagation path. A double phase three-dimensional relationship for HAPS and GEO systems is then presented. The comparison model present the analysis of atmospheric attenuation with specific focus on sand and dust based on particular size, visibility, adding gas effects for different frequency, and propagation angle to provide systems' operations with a predicted vision of satellite parameters' values. Thus, the proposed system provides wide range of selecting applicable parameters, under different weather conditions, in order to achieve better SNR for satellite communication.