• Title/Summary/Keyword: climatic factor

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Radar Data Correction for Long Distance Observation In Coastal Zone (해안지역 내 원거리 레이더관측자료의 보정에 관한 연구)

  • Ricardo S. TENORIO;Byung-Hyuk Kwon;Hong-Joo Yoon;Dong-In Lee
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.4 no.5
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    • pp.985-996
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    • 2000
  • In the coastal zone, to draw up short and medium range weather forecasts, mesoscale pluviogenic systems coming from the sea have to be observed in real time. These observations use remote sensing. However, satellite remote sensing is not sufficient to describe pluviogenic systems; reference to radar long distance observations is indispensable. This paper deals with the corrections, which must be made to long distance radar data if the rainfall field is to be both accurately and quantitatively defined. The error due to vertical variation in the reflectivity factor can be corrected from estimation of the mean profiles or by a climatic adjustment method. Atten-uation in the propagation can be corrected by an iterative polarimetric method. These various correc-tions permit the distance validity limits of radar data to be extended.

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A Study on Performance Analysis of 3kW Grid-Connected PV Systems (3kW급 계통연계형 태양광발전시스템의 성능특성 비교분석에 관한 연구)

  • So, Jung-Hun;Choi, Ju-Yeop;Yu, Gwon-Jong;Jung, Young-Seok;Choi, Jae-Ho
    • Journal of the Korean Solar Energy Society
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    • v.24 no.2
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    • pp.9-15
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    • 2004
  • 3kW grid connected PV(photovoltaic) systems have been constructed for evaluating and analyzing performance of PV system at FDTC(field demonstration test center) in Korea, PV systems installed in FDTC have been operating and monitored since November 2002. As climatic and irradiation conditions have been varied through long-term field test, data acquisition system has been constructed for measuring performance of PV system to observe the overall effect of environmental conditions on their operation characteristics. The performance of PV systems has been evaluated and analyzed for component perspective(PV array and power conditioning system) and global perspective(system efficiency, capacity factor, and electrical power energy) by field test. By the results, it is very important to develop optimal design technology of grid connected PV system.

Estimation of Non-Working Day Considering Weather Factors in Construction Projects - Based on Estimation Periods for Improving the Forecast - (건설공사의 기후요소에 의한 작업불능일 산정기준에 관한 연구 - 예측성 향상을 위한 산정기간 비교분석 중심으로 -)

  • Lee Keun-Hyo;Kim Kyung-Rai;Shin Dong-Woo
    • Proceedings of the Korean Institute Of Construction Engineering and Management
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    • 2004.11a
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    • pp.394-397
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    • 2004
  • Working-day calculation with weather factors of construction-site has estimated wethout proper data. They usually estimate it with their own experience and intuition. It causes not only economic loss to time-adjustment but also conflict with each participants. Moreover, weather estimation becomes worse than before, due to tendency of recently weather change. So, in this paper we present optimal estimation method as assessment by period of the arithmetical mean methods. For that, we analyse characteristic of the regions and weather change of temperature and rainfall which affects time.

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Plasticity of rice to water extremes: Farmers' genes to mechanisms

  • Bailey-Serres, Julia
    • Proceedings of the Korean Society of Crop Science Conference
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    • 2017.06a
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    • pp.5-5
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    • 2017
  • Too little and too much water due to climatic events is a significant cause of global food insecurity. Crops are less productive under water-limited conditions and all major crops, with the exception of rice (Oryza sativa), die within a few days of complete submergence. To complement our studies on genes such as SUB1A, (an ERF-VII transcription factor that provides robust submergence tolerance) and AG1 (a TREHALOSE 6-P PHOSPHATASE that promotes establishment of young seedlings underwater), we have retooled INTACT (${\underline{I}}solation$ of ${\underline{N}}uclei$ ${\underline{TA}}gged$ in specific ${\underline{C}}ell$ ${\underline{T}}ypes$) and TRAP (${\underline{T}}ranslating$ ${\underline{R}}ibosome$ ${\underline{A}}ffinity$ ${\underline{P}}urification$) for rice. These technologies enable us to follow dynamics in chromatin, nuclear pre-mRNAs and ribosome-bound mRNAs in meristems and diverse cell types. With these technologies we can better interpret responses to stresses and reestablishment of homeostasis. These include stress acclimation strategies involving changes in metabolism and development, such as dynamics in suberin deposition in sub-epidermal layers of roots that limit water loss under drought and oxygen escape during waterlogging. Our new data uncover dynamic and reversible regulation at multiple levels of gene regulation and provide new insights into processes of stress resilience. Supported by US NSF-PGRP Plasticity (IOS-1238243), Secretome (IOS-1546879) and REU (DBI-146129) grants.

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Effects of Thermophysiological Responses by Trainning Wear Made from Cotton and Hygroscopically Treated Polyester (면과 친수 가공 폴리에스테르 소재로 된 트레이닝복의 인체 생리 효과)

  • Chung Hee-Ja;Chang Jee-Hae
    • Journal of the Korean Home Economics Association
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    • v.37 no.12 s.142
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    • pp.193-203
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    • 1999
  • This study was executed to show influence of material and property of sportswear to physiological responses of body and comfort sensation and to supply basic research data about comfortable sportswear Trainning wear was manufactured with cotton(C) and hygroscopically treated polyester material (FP), and its properties of material were measured. Then rectal temperature, skin temperature, heart rate, weight loss, clothing microclimate and subjective sensation was estimated with study of wearing with these sportswear and examined the influence that it got to physiological responses of body and sensation. Health adult men were selected for subjects and executed at climatic chamber of temperature, $20\pm2^{\circ}C and humidity, $60\pm5%$ R.H. Conclusively sportswear of hygroscopically treated polyester is a favorable functional material. So far factor that affect to physiological comfort sensation has been explained mostly by moisture regain but in our experiment, it turned out that air permeability, water absorption velocity and dynamic oater absorption etc. were affecting factors. So according to this result, air permeability and moisture permeability should be considered with transmittance of temperature moisture for development of comfort material.

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Performance Monitoring Results, Evaluation and Analysis of 50kW Grid-Connected PV System (50kW급 계통연계형 태양광발전시스템의 성능모니터링 결과 및 평가분석)

  • So, Jung-Hun;Yu, Byung-Gyu;Hwang, Hye-MI;Yu, Gwon-Jong;Choi, Ju-Yeop
    • Journal of the Korean Solar Energy Society
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    • v.27 no.2
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    • pp.29-35
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    • 2007
  • Monitoring system is constructed for evaluating and analyzing performance of installed 50kW grid-connected PV system and have been monitored since October 2005. As climatic and irradiation conditions have been varied through long-term operation, there is necessity for evaluating numerical values of PV(Photovoltaic) system performance to observe the overall effect of environmental conditions on their operation characteristics. This paper presents performance monitoring results and analysis on component perspective(PV array and power conditioning system) and global perspective(yield, losses) of PV system for one year monitoring periods.

Estimation of Evapotranspiration in a Forest Watershed in Central Korea (중부(中部) 산림(山林) 지역(地域)의 증발산량(蒸發散量) 추정(推定))

  • Kim, Jesu
    • Journal of Korean Society of Forest Science
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    • v.88 no.1
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    • pp.86-92
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    • 1999
  • Evapotranspiration is one of important variables affecting ecosystem processes such as vegetation distribution and growth. It acts as a limiting factor for natural water resource management. The transpiration of vegetation is mainly determined by climatic factors. The lower slope of the study area was densely forested with Pinus densiflora S. et Z. of 8 m height, and the upper slope was covered with poorly grown Pinus densiflora S. et Z. and Quercus trees. The amount of evapotranspiration was estimated to 590.3 mm/yr by annual water budget method. The canopy resistance of Penman-Monteith model was determined as 99 s/m. Seasonal evapotranspiration can be estimated with the calculated evaporation and the canopy resistance. The amount of evapotranspiration peaked in May. That is considered from both the direct evaporation of intercepted rainfall and the transpiration of vegetation during the dry spring season.

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Evaluation and Application of Prediction Models for the Daylight Performance of a Light-Pipe System (광파이프 시스템의 채광성능 예측모델의 검증 및 적용)

  • Yun, Geun Young;Shin, Ju Young;Kim, Jeong Tai
    • KIEAE Journal
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    • v.10 no.1
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    • pp.65-72
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    • 2010
  • The use of natural light has the potential for improving both the energy efficiency and indoor environmental quality in buildings. A light-pipe system can introduce daylight to spaces that would otherwise not be able to benefit from the advantages of daylight penetration. For the light-pipe system to be widely used in Korea, it is important to quantify its daylighting performance with due consideration regarding the effects imposed by the local climate conditions. This paper presents the evaluation results of existing semi-empirical models to predict daylighting performance of a light-pipe system. The evaluation of the existing models was based on the monitoring data obtained from a underground parking lot in which the light-pipe system was installed. Comparisons were made between the predicted and the monitored data obtained from the study. The results indicated that semi-empirical models which was developed using the experimental data obtained under the Korean climatic conditions had a good prediction performance. We also quantified the effects caused by sky conditions, solar altitudes, room dimensions, and the aspect ratio of a light-pipe system on both the daylighting performance of the light-pipe system and the indoor illuminance distributions of the space using the semi-empirical model. Finally, this paper provides the design guideline of the light-pipe system for its application to an underground parking lot space.

Development of a Drought Detection Indicator using MODIS Thermal Infrared Data

  • Park, Sun-Yurp
    • Korean Journal of Remote Sensing
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    • v.20 no.1
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    • pp.1-11
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    • 2004
  • Based on surface energy balance climatology, surface temperatures should respond to drying conditions well before plant response. To test this hypothesis, land surface temperatures (LST) derived from MODIS data were analyzed to determine how the data were correlated with climatic water balance variables and NDVI anomalies during a growing season in Western and Central Kansas. Daily MODIS data were integrated into weekly composites so that each composite data set included the maximum temperature recorded at each pixel during each composite period. Time-integrated, or cumulative values of the LST deviation standardized with mean air temperatures had significantly high correlation coefficients with SM, AE/PE, and MD/PE, ranging from 0.65 to 0.89. The Standardized Thermal Index (STI) is proposed in this study to accomplish the objective. The STI, based on surface temperatures standardized with observed mean air temperatures, had significant temporal relationships with the hydroclimatological factors. STI classes in all the composite periods also had a strong correlation with NDVI declines during a drought episode. Results showed that, based on LST, air temperature observations, and water budget analysis, NDVI declines below normal could be predicted as early as 8 weeks in advance in this study area.

Estimating Reference Crop Evapotranspiration Using Artificial Neural Network and Temperature-based Climatic Data (인공신경망모형을 이용한 기온기반 기준증발산량 산정)

  • Lee, Sung-Hack;Kim, Maga;Choi, Jin-Yong;Bang, Jehong
    • Journal of The Korean Society of Agricultural Engineers
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    • v.61 no.1
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    • pp.95-105
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    • 2019
  • Evapotranpiration (ET) is one of the important factor in Hydrological cycle and irrigation planning. In this study, temperature-based artificial neural network (ANN) model for daily reference crop ET estimation was developed and compared with reference crop evapotranpiration ($ET_0$) from FAO-56 Penman-Monteith method (FAO-56 PM) and parameter regionalized Hargreaves method. The ANN model was trained and tested for 10 weather stations (5 inland stations and 5 costal stations) and two input climate factors, maximum temperature ($T_{max}$), minimum temperature ($T_{min}$), and extraterrestrial radiation (RA) were used for training and validation of temperature-based ANN model. Monthly reference ET by the ANN model also compared with parameter regionalized Hargreaves method for ANN model applicability evaluation. The ANN model evapotranspiration demonstrated more accordance to FAO-56 PM evapotranspiration than the $ET_0$ from parameter regionalized Hargreaves method(R-Hargreaves). The results of this study proposed that daily reference crop ET estimated by the ANN model could be used in the condition of no sufficient climate data.