• 제목/요약/키워드: coverage ratio

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유·무인 항공영상을 이용한 심층학습 기반 녹피율 산정 (Derivation of Green Coverage Ratio Based on Deep Learning Using MAV and UAV Aerial Images)

  • 한승연;이임평
    • 대한원격탐사학회지
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    • 제37권6_1호
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    • pp.1757-1766
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    • 2021
  • 녹피율은 행정구역면적 대비 녹지가 피복된 면적의 비율로, 실질적인 도시녹화 지표로 활용되고 있다. 현재 녹피율은 토지피복지도를 기반하여 산출되는데, 토지피복지도의 낮은 공간해상도와 일정하지 않은 제작시기는 정확한 녹피율 산출과 정밀한 녹피분석을 어렵게 한다. 따라서 본 연구는 새로운 녹피율 산출방안으로 항공영상과 심층학습을 활용한 방안을 제안한다. 항공영상은 높은 해상도와 비교적 일정한 주기로 정밀한 분석을 가능하게 하며 심층 학습은 항공영상 내 녹지를 자동으로 탐지할 수 있다. 지자체는 매년 다양한 목적을 위해 유인항공영상을 취득하여 이를 활용해 신속하게 녹피율을 산출한다. 하지만 미리 취득된 유인항공영상은 취득 시기와 해상도, 센서와 같은 세부사항을 선택할 수 없어 정밀한 분석이 어려울 수 있다. 이러한 한계점은 다양한 센서의 탑재가 가능하고 낮은 고도의 비행으로 인해 고해상도 영상을 취득할 수 있는 무인항공기를 활용하여 보완될 수 있다. 이에 두 가지 항공영상으로부터 녹피율을 산출하였고 그 결과, 모든 녹지 유형으로 부터 높은 정확도로 녹피율을 산출할 수 있었다. 하지만 유인항공영상으로부터 산출된 녹피율은 복잡한 환경에서 한계가 있었다. 이를 보완하고자 활용한 무인항공영상은 복잡한 환경에서도 높은 정확도의 녹피율을 산출할 수 있었고 추가밴드 영상을 통해 더 정밀한 녹지 영역 탐지가 가능했다. 추후 기존 유인항공영상에 새로 취득한 무인항공영상을 보완적으로 사용해 녹피율을 효과적으로 산출할 수 있을 것이라 기대된다.

식생피도가 식생여과대의 질소 및 인 처리효율에 미치는 영향 (Effect of Plant Coverage on the Treatment Efficiency of Nitrogen and Phosphorus in Vegetative Filter Strips)

  • 이병수;길경익
    • 한국물환경학회지
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    • 제24권4호
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    • pp.499-503
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    • 2008
  • In order to control the non-point source pollution, a vegetative filter strips (VFS) was set up and the site-monitoring was performed. The objective of this study is to investigate the influence of the plant coverage on treatment efficiency of total nitrogen (T-N) and total phosphorus (T-P) using vegetative filter strips. According to the results, it seemed that the treatment efficiencies of T-N and T-P were closely related with the plant coverage ratio. The results showed that treatment efficiency of T-P average 50% at higher than 50% of the plant coverage and 20~23% at lower than 50% of the plant coverage. Also, the treatment efficiency of T-N increased with the increase of the plant coverage ratio.

A Comparison Study for the Confidence Intervals of the Common Odds Ratio in the Stratified 2 X 2 Tables Using the Average Coverage Probability

  • Kwak, Min Jung;Jeong, Hyeong Chul
    • Communications for Statistical Applications and Methods
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    • 제10권3호
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    • pp.779-793
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    • 2003
  • In this paper, various methods for finding confidence intervals for common odds ratio $\psi$ of the K 2${\times}$2 tables are reviewed. Also we propose two jackknife confidence intervals and bootstrap confidence intervals for $\psi$. These confidence intervals are compared with the other existing confidence intervals by using Monte Carlo simulation with respect to the average coverage probability.

OFDMA 기반 Relay 시스템에서 Throughput 개선을 위한 자원 재사용과 커버리지 설정기법 (Frequency Reuse and Sub-cell Coverage Determination Scheme for Improved Throughput in OFDMA-based Relay Systems)

  • 현명륜;최호영;홍대형;임재찬
    • 한국통신학회논문지
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    • 제34권5A호
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    • pp.414-420
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    • 2009
  • 본 논문에서는 OFDMA 기반 relay 시스템에서 throughput 성능개선을 위한, Base Station (BS)과 Relay Station (RS)의 sub-cell 커버리지 설정기법을 제안한다. Relay 시스템에서는 BS-RS 링크에서 무선 자원을 추가로 소비하므로, RS간 자원의 재사용을 고려하면 자원의 효과적 사용이 가능하다. 그러나, 이때 신호의 간섭이 증가하므로 단말기의 수신 Signal to Interference and Noise Ratio (SINR)에 영향을 미치게 된다. 그리므로 본 연구에서는 자원 재사용 정도에 따른 사용가능 자원의 증가를 수신 SINR과 함께 sub-cell 커버리지 결정의 요인으로 함께 고려한다. 모의실험을 통한 결과분석을 통해 throughput 성능을 개선할 수 있는 sub-cell 커버리지를, 다양한 자원재사용 패턴에 따라 도출하였다.

공동주택 경관평가를 위한 시각밀도 지표에 관한 연구 입면차폐도와 규제지침을 중심으로 (An Visual Density Index for the Housing Landscape Evaluation Focused on the Elevation Coverage Index)

  • 강인호;이승미
    • 한국주거학회논문집
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    • 제15권3호
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    • pp.53-62
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    • 2004
  • Recently the landscape of housing has been emphasized. This trend seems to reflect the negative aspects of housing landscape in urban area. Throughout the analysis on the various visual density index, the following findings were obtained; 1) Elevation blockage ratio(EBR) was permitted differently according to the types of housing blocks, and the preference of block layout was different to the location of site. 2) EBR regulation level was acceptable. But 40m level of general area should be stepped up to the 35m level. 3) The correlation between the floor area ratio(FAR) and the EBR was not high. Therefore it is reasonable to regulate the EBR to the location. 4) Elevation coverage ratio(ECR) was highly correlated with the FAR. It means that FAR can substitute for the ECR, and ECR should be regulated to the level of FAR.

Noninformative Priors for the Ratio of the Failure Rates in Exponential Model

  • 조장식;백승욱
    • Journal of the Korean Data and Information Science Society
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    • 제13권2호
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    • pp.217-226
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    • 2002
  • In this paper, we derive noninformative priors for the ratio of failure rates in exponential model. A class of priors is found by matching the coverage probabilities of one-sided Baysian credible interval with the corresponding frequentist coverage probabilities. And we prove that the noninformative prior matches the alternative coverage probabilities and is a HPD matching prior up to the second order. Finally, we provide simulated freqentist coverage probabilities under the derived noninformative prior for small samples.

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위성영상과 토지피복도를 활용한 녹피율 산정방법 연구 (A Study on the Calculation Methods on the Ratio of Green Coverage Using Satellite Images and Land Cover Maps)

  • 문창순;심준영;김상범;이시영
    • 농촌계획
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    • 제16권4호
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    • pp.53-60
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    • 2010
  • This study aims at suggesting the attributes and limitations of each methods through the evaluation of the verified analysis results, so that it will be possible to select an efficient method that may be applied to assess the green coverage ratio. Green coverage areas of each sites subject to this study were assessed utilizing the following four methods. First, assessment of green coverage area through direct planimetry of satellite images. Second, assessment of green coverage area using land cover map. Third, assessment of green coverage area utilizing the band value in satellite images. Forth, assessment of green coverage area using and land cover map and reference materials. For this study, four urban zones of the City of Seosan in Chungcheongnam-do. As a result, this study show that the best calculation method is the one that combines the merits of first and second methods. This method is expected to be suitable for application in research sites of middle size and above. It is also deemed that it will be possible to apply this method in researches of wide area, such as setting up master plans for parks and green zones established by each local self-government organizations.

녹지의 규모와 기온저감효과와의 관련성에 관한 연구 (A Study on the Relation between Scale of Green Spaces and Decreasing Air Temperature)

  • 윤용한;배병호
    • 환경생물
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    • 제20권1호
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    • pp.10-19
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    • 2002
  • 녹지의 규모와 녹지내외의 기온저감효과와의 관련성을 명확히 밝히는 것을 목적으로 규모가 서로 다른 4개의 녹지를 대상으로 기온분포를 관측하였다. 그 데이터를 근거로 녹지내외의 기온분포, 녹지주변의 기온저감효과와 그 영향범위, 녹지내의 기온저감효과와 그 강도 및 토지피복비율과 기온, 그리고 녹지의 규모와 기온저감효과와의 관련성을 회귀분석 등에 의해 해석하였다. 그 결과, 토지피복현황의 차이가 기온변화에 영향을 미치고 있는 것을 알았다. 풍상과 풍하쪽의 기온저감효과의 영향범위를 비교하면, 풍하쪽에는 저온역이 형성되었고, 그 효과는 녹지의 규모가 크면 클수록 기온저감효과의 영향범위가 확대되었다. 더욱이 녹지내외의 기온저감효과는 녹지의 규모와 거의 비례하는 경향을 보였다

도시의 건폐율 및 용적률이 도시기후에 미치는 영향 분석 (Analysis on the Effects of Building Coverage Ratio and Floor Space Index on Urban Climate)

  • 여인애;이정재;윤성환
    • 한국태양에너지학회 논문집
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    • 제29권3호
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    • pp.19-27
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    • 2009
  • In this study, Urban Climate Simulation was performed by 3-Dimensional Urban Canopy Model. The characteristics of urban climate were analyzed combining artificial land coverage, building size, heat production from the air conditioning and topographic conditions as physical variables which affects urban climate characteristics. The results are as follows. (1) The aspects of the urban climatal change is derived to be related to the combination of the building coverage ratio, building height and shading area. According to the building height, the highest temperature was increased by $2.1^{\circ}C$ from 2-story to 5-story building and the absolute humidity by 2.1g/kg maximum and the wind velocity by 1.0m/s was decreased from 2-story to 20-story building. (2) Whole heat generation was influenced by the convective sensible heat at the lower building height and by the artificial heat generation at the higher one over 20-story building influence to some extent of the building coverage ratio. The effect of the altitude is not more considerable than the other variables as below $1^{\circ}C$ of the air temperature. In the last, deriving the combination of building coverage and building height is needed to obtain effectiveness of the urban built environment planning at the point of the urban climate. These simulation results need to be constructed as DB which shows urban quantitative thermal characters by the urban physical structure. These can be quantitative base for suggesting combinations of the building and urban planning features at the point of the desirable urban thermal environment as well as analyzing urban climate phenomenon.

Logit Confidence Intervals Using Pseudo-Bayes Estimators for the Common Odds Ratio in 2 X 2 X K Contingency Tables

  • Kim, Donguk;Chun, Eunhee
    • Communications for Statistical Applications and Methods
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    • 제10권2호
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    • pp.479-496
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    • 2003
  • We investigate logit confidence intervals for the odds ratio based on the delta method. These intervals are constructed using pseudo-Bayes estimators. The Gart method and Agresti method smooth the observed counts toward the model of equiprobability and independence, respectively. We obtain better coverage probability by smoothing the observed counts toward the pseudo-Bayes estimators in 2$\times$2 table. We also improve legit confidence intervals in 2$\times$2$\times$K tables by generalizing these ideas. Utilizing pseudo-Bayes estimators, we obtain better coverage probability by smoothing the observed counts toward the conditional independence model, no three-factor interaction model and saturated model in 2$\times$2$\times$K tables.