• Title/Summary/Keyword: 부정형

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The Development of Discharge Control Apparatus in Unsteady Flow for Analysis of Flood Control Effects in Detention Basin with Side Weir (강변저류지 홍수조절효과 분석을 위한 유량조절장치 개발)

  • Hong, Sang-Jin;Kim, Seo-Jun;Yoon, Byung-Man
    • Proceedings of the Korea Water Resources Association Conference
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    • 2011.05a
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    • pp.314-314
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    • 2011
  • 강변저류지는 하천변에 위치한, off-line 형 치수구조물로 하천의 수위 변화에 따라 저류량이 변한다. 그러므로 강변저류지의 홍수조절효과는 부정류 흐름 상태를 재현하여 모의해야 한다. 현재 국내에는 강변저류지 홍수조절효과 분석을 위해 주로 1차원 부정류 수치모형인 HEC-RAS를 사용하고 있다. 하지만 1차원 부정류 계산 결과에 대한 정확도 검증 없이 사용되고 있다. 따라서 이를 검증하고 보완할 수 있는 부정류 수리실험이 필요하다. 이에 본 연구에서는 상류 유입수문곡선을 재현할 수 있는 부정류 유량조절장치를 개발하였으며, 개발된 유량조절장치의 재현 능력을 검증하고 강변저류지 홍수조절효과 분석에 대한 적용 가능성을 확인하였다. 부정류 수리실험은 정규분포형 수문곡선과 이중 첨두를 가지는 수문곡선 및 다양한 첨두 지속시간을 갖는 수문곡선 형태에 대해 유량조절장치의 재현 능력을 검토하였다. 검토 결과 개발된 유량조절장치의 재현 수문곡선은 첨두 홍수량을 기준으로 약 1 % 이내의 오차를 보여 매우 만족스러운 결과를 얻었다. 향후 강변저류지의 홍수 조절효과 분석에 사용한다면 좀 더 현실적이고 정량적인 치수능력 평가가 될 수 있을 것이라 판단된다.

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Multi-Dimension Visualization Proposition and Clustering of Remote Sensing Data Using Star Coordinates Technique (Star Coordinates 기법을 이용한 원격탐사 데이터의 다차원 시각화 제안 및 클러스터링)

  • Kim, Dae-Sung;Kim, Yong-Il;Yu, Ki-Yun
    • 한국공간정보시스템학회:학술대회논문집
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    • 2005.05a
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    • pp.313-318
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    • 2005
  • 단 밴드 영상과는 달리 다차원 데이터는 분광적인 특성을 이용한 자동화된 영상 분석을 수행하는 장점이 있는 반면, 3차원 이상의 데이터를 분광차익 상에 시각화 하는데 어려움이 따른다. 클러스터링 기법을 이용한 영상 정보 추출은 자동화된 영상 분석적인 측면에서 중요한 분야 중 하나로서, 분광차원에서 구 형태의 조밀한 클러스터를 분리하는데 효과적인 방법으로 알려져 있지만 부정형(不定形)의 클러스터를 추출하는 방법에는 한계를 가진다. 따라서 본 연구는 모든 차원의 데이터를 2차원 상에 시각화하여 화소간 인접성을 개략적으로 확인할 수 있는 Star Coordinates 기법을 제안한다. 데이터의 다차원 시각화를 통해, 부정형 클러스터를 제거하여 다음 단계의 영상 분석 시 발생할 수 있는 오류를 방지할 수 있고, 명확한 클러스터를 확인 지정하여 클러스터링 정확도를 골일 수 있을 것으로 기대된다. 부가적인 연구고서, Star Coordinates 기법을 적용하여 Plot된 영상 데이터를 K-Means 알고리즘을 이용한 무감독 분류를 수행하여 그 결과를 확인하였다.

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A Study on Teaching $0^0$ in High School Mathematics (고등학교 수학에서 $0^0$의 지도 방안)

  • Kim, Dong-Hwa;Hong, Woo-Chorl
    • Communications of Mathematical Education
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    • v.24 no.2
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    • pp.283-300
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    • 2010
  • It has been recognized for a long time that high school students have difficulty in properly interpreting the form $0^0$. The treatment of $0^0$ was still a subject of a slight controversy among mathematicians until relatively recently. Since the mathematics curriculum in high school does not provide the definite treatment of $0^0$, some students might be inclined to ask what the value of the form is. In this research, we review materials dealing with $0^0$ and analyze historically and mathematically the form, whose true meaning is an indeterminate form. We identify the reality of the mathematics education in high school by conducting simple surveys targeting some high school teachers and the students who graduated from high schools recently. Then we discuss, for teachers and pre-service teachers, how to teach the form $0^0$ in high school mathematics.

Solution Algorithm of Unsteady Flow in a Dendritic Channel System (수지형 하천에서의 부정류 흐름의 해석 알고리즘)

  • Choi, Gye Woon
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.14 no.4
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    • pp.839-846
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    • 1994
  • This paper presents a simultaneous solution algorithm for one-dimensional unsteady flow routing through a dendritic channel system. This simulations solution algorithm is based on the double-sweep method and utilizes separate recursion equations for continuity, momentum and energy equations for each of the individual components of a dendritic channel system. Through separate recursion equations for each of the components. the new algorithm converts a dendritic channel network problem into a single-channel problem. The new algorithm is utilized in conjunction with a linearized unsteady flow model using full dynamic flow equations. The required computer storage for the coefficient matrix of the whole system is reduced significantly from the $2N{\times}2N$ matrix to a $2N{\times}4$ matrix, where N is the number of cross sections used in the computation of flow variables in a dendritic channel system. The algorithm presented in this paper provides an efficient and accurate modeling of unsteady flow events through a dendritic channel system.

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A study on types of AIDS perception : Focus on Q-methodology Application (AIDS인식 유형에 대한 연구 : Q방법론 적용을 중심으로)

  • Ahn, Lee-Su
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.17 no.10
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    • pp.46-53
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    • 2016
  • The purpose of this study is to analyze the cognizance of AIDS by applying the Q methodology, as well as to provide preliminary data for developing AIDS prevention campaigns. A Q population was identified from a literature search and in-depth interviews. The study process analyzed the P sample, the study participants, using the Q-sorting methodology to produce the Q sample, which is composed of statements from October 20 to 27, 2014. 20 participants (analyzed) 27 statements and 3 types of AIDS cognizance were produced as a result. These types are 1(N=9), 2(N=6), and 3(N=5), which correspond to denial, social support, and selfish motivation, respectively. The members of the denial type had a strongly negative opinion about AIDS, whereas the social support type showed a friendly gesture. The selfish motivation type took a neutral stance. The common and different points, as well as the distinctive features of these types, were studied. The accomplishments of this study include suggesting an efficient strategy for making an AIDS control policy, as well as a qualitative analysis, through the employment of the Q-methodology, which is useful for understanding human beings' (internal viewpoint).

Analysis of Corneal Topography for Korean College Students Based on Computer-Assisted Videokeratography (각막지형도 검사를 이용한 대학생의 각막형태에 대한 연구)

  • Lee, Seok-Ju;Ryu, Guen-Chang;Shin, Cheol-Guen;Seong, Jeong-Sub;Kim, In-Suk
    • Journal of Korean Ophthalmic Optics Society
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    • v.11 no.3
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    • pp.241-247
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    • 2006
  • Purpose : To define the distribution of normal corneal topographic patterns of Korean college students and compare them with previously published western data, Bogan et al's study. Methods : Computerized corneal topography was performed 220eyes normal subjects using CTK-922(Topography, swiss made). Mean age of the subjects was 23.2 yr.(range 19 to 57 yr.). The color-coded videokeratographs were classified by a masked observer according to the Bogan et al's classification such as round, oval, symmetric bow tie, asymmetric bow tie, and irregular. Results: The results revealed 57 eyes(25.9%) had round, 14 (6.4%) oval , 41(18.6%)symmetric bow tie, 78(35.5%) asymmetric bow tie, and 30(13.6%) irregular pattern. Conclusions : Our results of topographic patterns show the tendency of more irregular and less round topographic pattern in Korean college students, as compared to that of western adults.

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