• Title/Summary/Keyword: observation in field

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Spatial correlation-based WRF observation-nudging approach in simulating regional wind field

  • Ren, Hehe;Laima, Shujin;Chen, Wen-Li;Guo, Anxin;Li, Hui
    • Wind and Structures
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    • v.28 no.2
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    • pp.129-140
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    • 2019
  • Accurately simulating the wind field of large-scale region, for instant urban areas, the locations of large span bridges, wind farms and so on, is very difficult, due to the complicated terrains or land surfaces. Currently, the regional wind field can be simulated through the combination of observation data and numerical model using observation-nudging in the Weather Research and Forecasting model (WRF). However, the main drawback of original observation-nudging method in WRF is the effects of observation on the surrounding field is fully mathematical express in terms of temporal and spatial, and it ignores the effects of terrain, wind direction and atmospheric circulation, while these are physically unreasonable for the turbulence. For these reasons, a spatial correlation-based observation-nudging method, which can take account the influence of complicated terrain, is proposed in the paper. The validation and comparation results show that proposed method can obtain more reasonable and accurate result than original observation-nudging method. Finally, the discussion of wind field along bridge span obtained from the simulation with spatial correlation-based observation-nudging method was carried out.

Central nervous system depressant activity of Leucas aspera root

  • Rahman Shafiur;Sarder Mokaddez;Ali Yusuf;Rashid Abdur
    • Advances in Traditional Medicine
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    • v.6 no.3
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    • pp.174-178
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    • 2006
  • The ethanolic extract of Leucas aspera root was studied for its effect on the central nervous system (CNS) using pentobarbitone induced sleeping time test, the open field test and the hole cross test in Swiss albino mice. The present investigation revealed that the extract at the doses of 250 and 500 mg/kg, significantly prolonged the pentobarbitone induced sleeping time in mice though the onset of sleep was delayed as compared to control. In open field test the depressing effect was prominent from the second observation period (30 min) and persisted throughout the entire experimental period (240 min). In the hole cross test, the depressing effect was observed significant from the third observation period (60 min) and persisted up to the seventh observation period (240 min) except at fourth observation (90 min) for 250 mg dose group and depressing effect was significant from second observation (30 min) up to seventh observation period (240 min) for 500 mg dose group. These results support the finding that Leucas aspera root may contain biologically active constituent(s) having CNS activity.

DETERMINATION OF USER DISTRIBUTION IMAGE SIZE AND POSITION OF EACH OBSERVATION AREA OF METEOROLOGICAL IMAGER IN COMS

  • Seo, Jeong-Soo;Seo, Seok-Bae;Kim, Eun-Kyou;Jung, Sung-Chul
    • Proceedings of the KSRS Conference
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    • v.1
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    • pp.228-231
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    • 2006
  • In this paper, requirements of Meteorological Administration about Meteorological Imager (MI) of Communications, Ocean and Meteorological Satellite (COMS) is analyzed for the design of COMS ground station and according to the analysis results, the distribution image size of each observation area suitable for satellite Field Of View (FOV) stated at the requirements of meteorological administration is determined and the precise satellite FOV and the size of distribution image is calculated on the basis of the image size of the determined observation area. The results in this paper were applied to the detailed design for COMS ground station and also are expected to be used for the future observation scheduling and the scheduling of distribution of user data.

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Capability Assessment on Meteorological Technology - Comparative Study of Technological Prowess on Korea, U.S., and Japan - (국가 기상기술력 수준 평가 - 한국, 미국, 일본을 대상으로 한 비교 연구 -)

  • Kim, Se-Won;Park, Gil-Un;Cho, Changbum;Lee, Young-Gon;Yim, Deok-Bin
    • Atmosphere
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    • v.21 no.3
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    • pp.319-336
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    • 2011
  • The objective of this study was to assess the meteorological capability of Korea by comparing with that of the U.S. and Japan as of 2010. The research was conducted based on various indices and surveys, and quantified the results using the Gordon's scoring model. The index assessment used 11 items derived from 9 segments - surface observation, advanced observation and observations quality in the observation field; data assimilation, numerical model and infrastructure in the data processing field; forecast accuracy in the forecast field; climate prediction and climate change in the climate field - in this research, we classified the meteorological technology into four fields. In the survey assessment, another 10 items in addition to the above 11 ones (total 21 items) were used. In the field of climate, Korea was found to lag far behind the U.S. (96.5p) and Japan (90.5p) with 77.6 points out of 100, which is 18.9 and 12.9 points lower than them respectively. On the other hand, Korea showed the narrowest gap with Japan (95.3p) and the U.S. (94.2) in the forecasting field, recording 90.3 points. Particularly, in surface observation, infrastructure and forecast accuracy segment, Korea was on a par with the U.S. and Japan, boasting 100.5 percent compared to their counterparts. However, in advanced observation, data quality and climate change segment, Korea was only at the level of 81.5 percent compared to that of the U.S. and Japan. All in all, the technological prowess of Korea, scoring 84.6 points, stood at 89.7 percent of that of the U.S. (94.3p) and 91.9 percent of Japan (92.1p).

Development and Application of Astronomical Observation Program for Field Trip (현장학습을 위한 천체관측 프로그램의 개발과 적용)

  • Kim, Sang-Dal;Park, Jong-Chul
    • Journal of the Korean Society of Earth Science Education
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    • v.1 no.1
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    • pp.52-62
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    • 2008
  • The purpose of this study is to find out learning content for astronomical observation that could perform astronomical programs regardless of weather conditions as a case for the present conditions of astronomical observation and the methods of new education for astronomical observation, and to suggest the methods of synchronized multiple astronomical observation and actual cases using the Internet network. The results are as follows. First, the method of galaxy-oriented astronomical education helped those attempting to approach astronomy academically for the first time grasp useful concepts as to the astronomical space, and let them look at the space in an objective sense, which was effective in forming cosmic structure and concepts. Second, the administration curriculum of astronomical observation team was related to data that systematically contained annual astronomical education concerning the operation of astronomical observation teams; thus, they could be suggested as beneficial teaching materials to the teachers who wanted to organize a school club meeting. Third, it has been noted that the level of students' satisfaction in p2d program and MSO program was very high, and they turned out to be effective learning methods that could be implemented even in times of rain when it would not be possible to conduct astronomical observation activities.

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Diagnostics of Observation Error of Satellite Radiance Data in Korean Integrated Model (KIM) Data Assimilation System (한국형수치예보모델 자료동화에서 위성 복사자료 관측오차 진단 및 영향 평가)

  • Kim, Hyeyoung;Kang, Jeon-Ho;Kwon, In-Hyuk
    • Atmosphere
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    • v.32 no.4
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    • pp.263-276
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    • 2022
  • The observation error of satellite radiation data that assimilated into the Korean Integrated Model (KIM) was diagnosed by applying the Hollingsworth and Lönnberg and Desrozier techniques commonly used. The magnitude and correlation of the observation error, and the degree of contribution for the satellite radiance data were calculated. The observation errors of the similar device, such as Advanced Technology Microwave Sounder (ATMS) and Advanced Microwave Sounding Unit-A shows different characteristics. The model resolution accounts for only 1% of the observation error, and seasonal variation is not significant factor, either. The observation error used in the KIM is amplified by 3-8 times compared to the diagnosed value or standard deviation of first-guess departures. The new inflation value was calculated based on the correlation between channels and the ratio of background error and observation error. As a result of performing the model sensitivity evaluation by applying the newly inflated observation error of ATMS, the error of temperature and water vapor analysis field were decreased. And temperature and water vapor forecast field have been significantly improved, so the accuracy of precipitation prediction has also been increased by 1.7% on average in Asia especially.

Field Observation on Wave Induced Liquefaction in Sea-bed and its Analysis (파랑에 의한 해저지반의 액상화에 관한 현지관측과 해석)

  • 이익효;선공기
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.3 no.2
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    • pp.100-107
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    • 1991
  • The purposes of this study are 1) to observe the wave-induced liquefaction in the oceanic seabed. 2) to verify the liquefaction theory proposed by the Authors. The study consists of the field observation and theoretical analysis on the wave-induced liquefaction. In the field observation. The sea bottom pressures. the fluctuating pore pressures and stresses in the seabed and the changes of the water depth were observed for two years. The liquefaction theory proposed by the Authors is verified by the comparing the calculated fluctuating pore pressures with those observed in the field.

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Evaluation of the Harbor Operation Rate Considering Long Period Waves (장주기파를 고려한 항만 가동율의 평가)

  • 김규한
    • Journal of Ocean Engineering and Technology
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    • v.16 no.2
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    • pp.21-26
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    • 2002
  • In this study, the characteristics of long period waves are analyzed by field observation at Sokcho harbor on the eastern coast of Korea. firstly. the pressure data obtained from field observation are transformed into water surface elevations and the wave by wave analysis is applied to the observed wave data. also, we select long period waves by setting up the range 30-200sec, and suggest the relationship between ordinary waves and long period waves using the concept of the significant wave height. and, we examine the effects oft he long period waves on the rate of the harbor operation. The observation results demonstrate that the long period waves with heights of 1.2-14.6cm and periods of 35.8-162sec exist at Sokcho harbor. also, we found the rates of harbor operation based on long period waves are 61.8%-99.5% lower than the usual rates of 93.8%-100%.

Information for Urban Risk Management: the Role of Remote and Close Sensing

  • Hofstee, Paul;Genderen, John van
    • Proceedings of the KSRS Conference
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    • 2003.11a
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    • pp.162-164
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    • 2003
  • The multi-disciplinary research project Strengthening Local Authorities in Risk Management (SLARIM), initiated by ITC, includes three case study cities in Asia. An important question is: what are the essential data for risk management and how to access such data. The role of common sources (e.g. census data), data derived from remote sensing (high-resolution satellite imagery, aerial photos), and data from close sensing (field observation, including mobile GIS) to acquire essential risk management data will be discussed. Special attention is given to the question of the minimum area and to disaggregating population data. A few examples are given of Kathmandu / Lalitpur, Nepal.

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Drawing Elements of Inquiry in Field Geology and Analyzing Field Geology Education in Previous Studies (야외 지질학 탐구 요소 추출 및 지질 답사 교육 문헌 분석)

  • Jung, Chanmi;Shin, Donghee
    • Journal of The Korean Association For Science Education
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    • v.37 no.3
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    • pp.465-481
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    • 2017
  • This study is a research synthesis analyzing how field geology education is conducted in domestic and foreign countries in the recent 20 years and how it reflects the characteristics of authentic geologic inquiry. For these purposes, we first drew five elements of inquiry in field geology (observation, representation, abductive reasoning, spatial thinking, and diachronic thinking) considering the field geologists' actual research method as well as its pedagogical significance in science education. We developed analysis criteria for field geology education. The 53 cases were analyzed based on each element of inquiry in field geology and its sub-elements, and also the tendency of overall elements. As a result, observation and representation were included in most cases, but there appeared less frequency in order of abductive reasoning, spatial thinking, and diachronic thinking. For observation, the ratio of purposive observation and autonomous observation is high. For representation, both visualizing and linguistic type of representation and free-form representation appear frequently. For abductive reasoning, the step of generating hypothesis is often included and the hypothesis tends to be about the geological formatting process. For spatial thinking, type of self-location and perception of the spatial configuration of the structure appear at a high rate. For diachronic thinking, type of stratigraphic sequence is the most frequent. The proportions of the cases including three or more elements of inquiry in field geology consist 87% of the total. We suggested implications for improving geological fieldwork as authentic science inquiry in the future.