• Title/Summary/Keyword: observation gaps

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A Study on the Air Temperature Changes and Regional Characteristics in South Korea (우리나라 지역별 기온변화 특성)

  • Kim, Tae Ryong
    • Journal of Integrative Natural Science
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    • v.2 no.2
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    • pp.131-167
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    • 2009
  • Global warming is regarded as one of the most critical issues that should be taken care of by the entire global community as it threatens the survival of mankind. South Korea, in particular, undergoes faster warming than the average rate of global warming. South Korea has revealed various warming rates and trends being surrounded by sea on three sides and having complex terrains dominated by mountains. The rates vary according to regions and their urbanization and industrialization. Differences also derive from seasons and weather elements. Changes to the highest, mean, and lowest temperature are also different according to the characteristics of regions and observatories, which is more apparent where the force of artificial weather applies. In an urban area, temperature gaps tend to decrease as the lowest temperature rises more than the highest temperature. Meanwhile, temperature gaps grow further in a coastal or country region where the force of artificial weather is small and the force of natural weather prevails. In this study, the investigator analyzed the changes to the weather elements of 11 observation spots that had gone through no changes in terms of observation environment since 1961, were consecutively observed, and had the quality of their observation data monitored on an ongoing basis. Using the results, I tried to identify natural and artificial causes affecting certain spots. Located on the east coast of the Asian Continent, South Korea sees weather changing very dynamically. Having huge influences on our weather, China has achieved very rapid industrialization for the last 30 years and produced more and more greenhouse gases and air pollution due to large-size development projects. All those phenomena affect our weather system in significant ways. Global warming continues due to various reasons with regional change differences. Thus the analysis results of the study will hopefully serve as basic data of weather statistics with which to set up countermeasures against climate changes.

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An Ethnography on Educational Activities of Three Middle Schools in Rural Area (농산어촌지역 교육의 특성과 문제점 분석 -세 학교에 대한 문화기술적 접근-)

  • Lee, Doo-Hyoo
    • Journal of Agricultural Extension & Community Development
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    • v.18 no.3
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    • pp.435-483
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    • 2011
  • This paper was to study characteristics of school types based on classification of rural areas. This study tried to provide basic data for implementing the development of rural education policy for the community unit by classifying and analyzing administrative districts. For the purpose, the researcher carried out literature reviews and selected three schools considering the gaps in size and location of rural community. The researcher interviewed teachers and parents, to gather information about rural education, and conducted participant observation on educational activities. As a result, this study showed each rural school has its own distinct characteristics by the school types corresponding to each rural community. Characteristics with school types were influenced by school location, possible migration into the cities, possible opportunities of private tutoring, school size, social class distribution, socio-economic status, dwelling pattern of school teachers. In conclusion, it is important that the educational policies for rural area consider the different characteristics of rural schools.

Photonic Band Gaps for Surface Plasmon Modes in Dielectric Gratings on a Flat Metal Surface

  • Song, Seok-Ho;Yoon, Jae-Woong;Lee, Gwan-Su;Oh, Cha-Hwan;Kim, Pill-Soo
    • Journal of the Optical Society of Korea
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    • v.6 no.3
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    • pp.76-82
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    • 2002
  • For dielectric gratings on a flat metal surface, photonic band gaps created by Brags scattering of surface plasmon polaritons are observed. The observation result that directly images this gap is compared with that predicted by a numerical model based on a plane wave expansion. Consistency between the experimental and numerical results is also confirmed by comparison with the well-known calculation method of diffraction, the rigorous coupled wave analysis method.

An Observational Study on the Change of Micro-meteorological Environment due to Deforestation (삼림파괴로 인한 미기후 환경변화에 관한 관측적 연구)

  • Lim, Jung-Sub;Lee, Bu-Yong;Kim, Hae-Dong;Kim, Hak-Yoon;Hwang, Soo-Jin
    • Journal of the Korean earth science society
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    • v.30 no.2
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    • pp.185-195
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    • 2009
  • We investigated the change of several meteorological variables due to deforestation. We established two sets of automatic weather observation system: one on a hill where forest was destructed by lumbering (Point 1) and the other in a neighboring district (Point 2) of fairly preserved forest. The observations were continued for one year (2006. 12-2007. 12). In this study, we analysed the data observed for one week from the nea day after summertime rainfall. The results showed that the air temperatures of Point 1 were about $1.5^{\circ}C$ higher than those of Point 2 during the daytime. But there were small gaps between the two poults during the nighttime. The relative humidities also differed greatly between the two during the daytime. It was as high as about 10% at Point 2. The surface and underground (15 cm in depth) soil temperatures were also fealty different between the two points during the daytime. They were $3-10^{\circ}C$ higher at Point 2 than those of Point 1. And the gaps reduced drastically during the nighttime. The averaged soil moistures were 7.1% at Point 1 and 19.5% at Point 2 during the observation period, respectively. The differences of wind direction were small, but the wind speeds differed between the two points. The observed wind speeds during the observation period were roughly estimated to be about 0.5m/s at Point 1 and 0.3m/s at Point 2. The heat budget analysis was also performed based on the observation data.

Bias-correction of Dual Polarization Radar rainfall using Convolutional Autoencoder

  • Jung, Sungho;Le, Xuan Hien;Oh, Sungryul;Kim, Jeongyup;Lee, GiHa
    • Proceedings of the Korea Water Resources Association Conference
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    • 2020.06a
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    • pp.166-166
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    • 2020
  • Recently, As the frequency of localized heavy rains increases, the use of high-resolution radar data is increasing. The produced radar rainfall has still gaps of spatial and temporal compared to gauge observation rainfall, and in many studies, various statistical techniques are performed for correct rainfall. In this study, the precipitation correction of the S-band Dual Polarization radar in use in the flood forecast was performed using the ConvAE algorithm, one of the Convolutional Neural Network. The ConvAE model was trained based on radar data sets having a 10-min temporal resolution: radar rainfall data, gauge rainfall data for 790minutes(July 2017 in Cheongju flood event). As a result of the validation of corrected radar rainfall were reduced gaps compared to gauge rainfall and the spatial correction was also performed. Therefore, it is judged that the corrected radar rainfall using ConvAE will increase the reliability of the gridded rainfall data used in various physically-based distributed hydrodynamic models.

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How Derivational Prefix Instruction Impacts Incidental Vocabulary Acquisition and Reading Comprehension

  • Choi, Sung-Mook
    • English Language & Literature Teaching
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    • v.13 no.3
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    • pp.1-22
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    • 2007
  • The study examined the effects of explicit derivational morphology instruction (henceforth DMI) on the incidental vocabulary acquisition and reading comprehension of 132 Korean 1st-year high school students who responded to a battery of tests (two vocabulary tests and a reading comprehension test). Multiple statistical tools were used to analyze the data: Analysis of Covariance (ANCOVA), Analysis of Variance (ANOVA), Simple Regression Analysis, Tests of Simple Main Effects, and effect size computation using Cohen's d. The results indicated that (a) DMI enhanced students' ability to infer word meanings in context, (b) DMI promoted high proficiency students' reading comprehension, whereas it impeded intermediate proficiency students' reading comprehension, (c) vocabulary knowledge has a strong positive predictive value for reading comprehension, and (d) the gaps of vocabulary knowledge across proficiency levels were still substantial, despite the observation that DMI promoted students' vocabulary acquisition. These results have a bearing on English as Foreign Language (EFL) reading pedagogy.

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Observation of Oxide Film Formed at Si-Si Bonding Interface in SFB Process (SFB 공정시 Si-Si 집합 계면에 형성되는 산화막의 관찰)

  • 주병권;오명환;차균현
    • Journal of the Korean Institute of Telematics and Electronics A
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    • v.29A no.1
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    • pp.41-47
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    • 1992
  • In SFB Process, after 110$0^{\circ}C$ annealing in wet OS12T(95$^{\circ}C$ HS12TO bubbling) atmosphere, the existence of the interfacial oxide film in micro-gap at Si-Si bonding interface was identified. The angle lapping/staining and SEM morphologies of bonding interface showed that the growing behavior of interfacial oxide made a contribution to eliminate the micro-gaps having a width of 200-300$\AA$. In case of the diodes composed of p-n wafer pairs made by SFB processes, the annealed one in wet OS12T atmosphere exhibited a dielectric breakdown phenomena of interfacial oxide at 37-40 volts d.c.

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Elucidation of triggering characteristics for a trigatron spark gap by measuring UV light (자외선측정(紫外線測定)에 의한 트리거트론시동특성(始動特性)의 해명(解明))

  • Ko, K.C.;Ishii, S.;Chang, Y.M.;Kang, H.B.
    • Proceedings of the KIEE Conference
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    • 1989.11a
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    • pp.142-144
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    • 1989
  • Triggering characteristics of a trigatron spark gap have been studied by measuring self-emission UV light. By combining the measurement of the UV light with that of the trigger gap voltage and the lain discharge current, we distinguished clearly the differences between the trigatron operations in which the lain discharge occurs after the trigger discharge in the case of sale polarity between the trigger pin and the lain electrode at the opposite side, and the lain gap breakdown takes place before the formation of the trigger spark in the case of different polarity. We show the observation of UV radiation with the other electromagnetic measurements is a simple and reliable scheme to investigate the triggering properties of the trigatron spark gaps.

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Behavior and Hysteresis Characteristics of Traditional Timber Framers under Lateral Load (전통 문화재 목조 프레임의 횡하중에 대한 거동 및 이력특성)

  • 이필성
    • Proceedings of the Earthquake Engineering Society of Korea Conference
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    • 1999.10a
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    • pp.396-403
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    • 1999
  • This experimental study investigates the hysterestic behavior of traditional timber frames subjected to lateral loads. Prototype frames for this study were selected from one of typical national treasures for timber structures in Korea. For simplicity roof structures and braket systems were excluded from specimens and the joint behavior of beam-to-column system were presumed to have crucial effect on their global behavior. The experimental observation showed stiffness degradation and slip after experiencing initial yield and the first cycle at a new larger displacement due to inherent gaps in traditional timber connection and gradual indentation of interfaces, The cyclic behaviors of all specimens were similar to those os modern timber frames with bolt and nail connections. Additional structural members such as an upper beam and clay-filled wall increased the initial stiffness strength and energy dissipation. It is expected that collapse of Korean traditional timber frames under lateral load is mainly caused from P-$\Delta$ effects rather than local member failure.

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Missing Pattern Analysis of the GOCI-I Optical Satellite Image Data

  • Jeon, Ho-Kun;Cho, Hong Yeon
    • Ocean and Polar Research
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    • v.44 no.2
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    • pp.179-190
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    • 2022
  • Data missing in optical satellite images caused by natural variations have been a crucial barrier in observing the status of marine surfaces. Although there have been many attempts to fill the gaps of non-observation, there is little research to analyze the ratio of missing grids to overall sea grids and their seasonal patterns. This report introduces the method of quantifying the distribution of missing points and then shows how the missing points have spatial correlation and seasonal trends. Both temporal and spatial integration methods are compared to assess the effectiveness of reducing missing data. The temporal integration shows more outstanding performance than the spatial integration. Moran's I and K-function with statistical hypothesis testing show that missing grids are clustered and there is a non-random distribution from daily integration. The result of the seasonality test for Moran's I through a periodogram shows dependency on full-year, half-year, and quarter-year periods respectively. These analysis results can be used to deduce appropriate integration periods with permissible estimation errors.