• 제목/요약/키워드: L-Curve

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수질오염총량제도 유역의 수질 및 부하량 평가를 위한 웹기반 LDC 시스템의 적용 (Application of Web-based Load Duration Curve System to TMDL Watersheds for Evaluation of Water Quality and Pollutant Loads)

  • 강현우;류지철;신민환;최중대;최재완;신동석;임경재
    • 한국물환경학회지
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    • 제27권5호
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    • pp.689-698
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    • 2011
  • In South Korea, Total Maximum Daily Load (TMDL) has been enforced since 2004 to restore and manage water quality in the watersheds. However, the appraisal of TMDL in South Korea has lots of weaknesses to establish the plan for recovery of water quality because it just evaluates the target water quality during the particular flow duration interval. In the United States, Load Duration Curve (LDC) method bas been widely used in the TMDL to evaluate the water quality and pollutant loads considering variation of stream flow. In a recent study, web-based Load Duration Curve system was developed to create the LDC automatically and provide the convenience of use. In this study, web-based Load Duration Curve system was applied in the Gapyeongcheon watershed using the daily flow and 8-day interval water quality data, and Q-L Rating Curve was used to evaluate the water quality and pollutant load in the watershed, also. As a result of study, water quality and pollutant load in Gapyeongcheon watershed were met with water quality standard and allocated load in the all flow durations. Web-based Load Duration Curve system could be applied to the appraisal of South Korean TMDL because it can be used to judge the impaired flow duration and build up the plan of load reduction, and it could enhance the publicity. But, web-based Load Duration Curve system should be enhanced through addition of load assessment tools such as Q-L rating curve to evaluate water quality and pollutant load objectively.

L-곡선 기반의 Modified Wiener Filter(MWF)를 이용한 위성 영상의 MTF 보상 (A MTF Compensation for Satellite Image Using L-curve-based Modified Wiener Filter)

  • 전병일;김홍래;장영근
    • 대한원격탐사학회지
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    • 제28권5호
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    • pp.561-571
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    • 2012
  • 변조전달함수(MTF; Modulation Transfer Function)는 광학영상의 성능을 평가하는 중요한 품질 요소 중 하나이다. 영상의 MTF 증진을 위해 영상 복원이 필요하나, 이 과정은 대표적인 부적합문제(ill-posed problem)의 하나로 특정한 해를 갖지 않는다. 영상 복원을 위한 필터에는 역 필터(IF; Inverse Filter), 의사 역 필터(PIF; Pseudo Inverse Filter), Wiener Filter(WF) 등이 있다. 이들 중 가장 일반적으로 사용되고 있는 WF는 촬영된 영상 내에서 영상과 잡음을 정확히 구분하기 어렵다는 한계를 가지고 있다. 본 논문에서는 Modified Wiener Filter(MWF)를 사용하여 부적절 문제를 풀 수 있도록 문제를 정규화 하였으며, 정규화 변수(regularization parameter)의 값을 찾기 위한 방법으로 L-곡선(L-curve)을 사용하였다. MWF의 검증을 위해 Dubaisat-1 위성의 영상을 의사 역 필터(PIF), Wiener Filter(WF), MWF로 영상 복원을 수행하였다. 복원 결과, MWF를 사용했을 때가 PIF를 사용했을 때의 결과에 비해 20.93%, WF를 사용했을 때의 결과에 비해 10.85% 더 향상된 MTF를 얻을 수 있었다.

A crofton style formula and its application on the unit sphere $ *$

  • Y. D. Chai;Lee, Young-Soo
    • 대한수학회보
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    • 제33권4호
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    • pp.537-544
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    • 1996
  • Crofton's formula on Euclidean plane $E^2$ states: Let $\Gamma$ be a rectifiable curve of length L and let G be a straight line. Then $$ \int_{G \cap \Gamma \neq \phi} n dG = 2L $$ where n is the number of the intersection points of G with the curve $\Gamma$.

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전력량 예측 및 부하 패턴을 근거로 한 부하 곡선 예측 (Electric Energy Forecasting and Development of Load Curve Based on the Load Pattern)

  • 지평식;조성현;이종필;남상천;임재윤;김정훈
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1996년도 추계학술대회 논문집 학회본부
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    • pp.163-165
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    • 1996
  • In this paper, we are proposed development of electric energy method and load curve. A daily electric energy is forecasted using artificial neural network. The load curve is obtained by combining forecasted electric energy and typical daily load patterns which are classified using KSOM and Fuzzy system. As a result, we know that we could get more accurate results and easier application than the results from based on the hourly historical data.

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지니계수를 통한 농촌어메니티 자원 집중화 연구 (Understanding Distributional Attributes of Rural Amenity Resources using Gini's Coefficient)

  • 이상현;최진용;오윤경;배승종
    • 농촌계획
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    • 제16권2호
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    • pp.57-64
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    • 2010
  • This study aims to understand the degree of inequality of surveyed amenity resources and identify which resource and region have the highest concentration by estimating Lorenz Curve and the Gini's Coefficient. The Lorenz Curve and Gini's Coefficient derived from economics are introduced as tools for investigating and quantifying regional variability of amenity resources concentration. This study describes the concepts underlying the application of the Gini's coefficient to measure the concentration of amenity resources in 11 regions, Chungbuk Province, Korea. The Lorenz Curve presents a graphical view of the cumulative distribution of amenity resources and the Gini's Coefficient provides a single-parameter measure of the distributional concentration of amenity resources. Also the Gini's Coefficient is compared to the number of amenity resource for understanding distributional difference between concentration and quantitative distribution of amenity resources. The results demonstrate significantly different regional variation according to the amenity variables: almost intact nature, interaction between nature and man, man-made.

A UNIFORM ESTIMATE ON CONVOLUTION OPERATORS WITH THE ARCLENGTH MEASURE ON NONDEGENERATE SPACE CURVES

  • Choi, Youngwoo
    • Korean Journal of Mathematics
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    • 제6권2호
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    • pp.291-298
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    • 1998
  • The $L^p-L^q$ mapping properties of convolution operators with measures supported on curves in $\mathbb{R}^3$ have been studied by many authors. Oberlin provided examples of nondegenerate compact space curves whose arclength measures enjoy $L^p$-improving properties. This was later extended by Pan who showed that such properties hold for all nondegenerate compact space curves. In this paper, we will prove that the operator norm of the convolution operator with the arclength measure supported on a nondegenerate compact space curve depends only on certain quantities of the underlying curve.

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삼림군집구조 조사를 위한 조사구 크기에 관한 연구(I) -소백산지역 활엽수혼효림군집 교목층의 적정 조사구수- (Plot Size for Investigating Forest Community Structure(I) -Adequate Number of Plots of Tree Stratum in a Mixed Deciduous Forest Community at Sobaeksan Area-)

  • 박인협;이경재;조재창
    • 한국환경생태학회지
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    • 제6권2호
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    • pp.162-167
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    • 1993
  • 빈도측정을 고려 한 삼림군립구조 조사시 교목층의 적정 조사구수를 결정하기 위하여 우점종인 물푸레나무의 중요치가 28.1%인 소백산지역 활엽수혼효림군집의 교목층을 대상으로 20개의 l0m $\times$ l0m 조사구를 설치한 후 종수-면적 곡선, performance curve, 통계학적 방법 등을 적용하였다. 종수-면적 곡선에 있어서 누적조사구수의 증가율보다 출현종수의 증가율이 낮은 최소 조사구수는 8개이었으며, 누적조사구수의 증가율에 비하여 출현종수의 증가율이 1/2 이하인 최소 조사구수는 11개이었다. 주요수종의 중요치에 의한 performance curve를 작성한 결과 우점종과 준우점종의 구분이 뚜렷해지는 최소 조사구수는 5개이었으며, 준우점종간의 구분도 뚜렷해지는 최소조사구수는 10개이었다. 따라서, 삼림군집 구조의 기본적인 측도인 출현종수와 중요치를 고려할 때 본 조사지에 있어서 l0m $\times$ l0m 교목층 조사구의 적정 조사구수는 10개인 것으로 나타났다. 이때, 군집을 대표한다고 할 수 있는 20개 전체조사구와의 유사도지수는 90% 이상이었으며, 모집단인 군집 종다양도에 대한 신뢰구간은 $\pm$0.073이었다.

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최적 곡선반경-완화곡선장 결정에 관한 연구 (A Study on Determination Method of Optimum Radius and Transition Curve Length)

  • 엄주환;양신추;강윤석;황성호
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 2008년도 추계학술대회 논문집
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    • pp.1084-1089
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    • 2008
  • In this paper, a method for determining the boundary conditions which are derived from the random obstacles on the curves was presented. An algorism using this method is also developed. This determination method can be used for a good engineering tool in optimal curve design and an Radius-transition curve length(R-$L_t$) combination within the permissible zone can be improved without any increased costs.

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Divide Knot Presentation of Knots of Berge's Sporadic Lens Space Surgery

  • Yamada, Yuichi
    • Kyungpook Mathematical Journal
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    • 제60권2호
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    • pp.255-277
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    • 2020
  • Divide knots and links, defined by A'Campo in the singularity theory of complex curves, is a method to present knots or links by real plane curves. The present paper is a sequel of the author's previous result that every knot in the major subfamilies of Berge's lens space surgery (i.e., knots yielding a lens space by Dehn surgery) is presented by an L-shaped curve as a divide knot. In the present paper, L-shaped curves are generalized and it is shown that every knot in the minor subfamilies, called sporadic examples of Berge's lens space surgery, is presented by a generalized L-shaped curve as a divide knot. A formula on the surgery coefficients and the presentation is also considered.