• Title/Summary/Keyword: 자유흐름

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Study on the use of river water in the downstream basin of ChungjuDam (충주댐 하류 유역의 하천수 사용에 대한 고찰)

  • Jeong, Ji-Hun;Lee, Dong-Kyu;Jeong, Seung-Gyo;HwangBo, Jong-Gu
    • Proceedings of the Korea Water Resources Association Conference
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    • 2022.05a
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    • pp.364-364
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    • 2022
  • 최근 기후변화에 따른 잦은 이상 가뭄으로 물 부족 현상이 심화되고 있어 물 안보가 중요한 사회적 이슈로 부각되고 있다. 물 부족에 대비하기 위해 수자원은 인류가 마음대로 사용할 수 있는 자유재가 아니라 보호·관리하여야 하는 대상으로, 보유한 미사용량을 회수·재배분하여 물 이용의 공정성을 강화 등 물 이용 제도의 전반에 대한 검토·개선이 필요한 실정이다. 하지만 일부 유역에서는 하천수 사용량이 정확하게 계측되지 않아 공정한 하천수 배분 등에 한계가 발생하고 있다. 본 연구에서는 충주댐 하류 유역에 위치한 자동유량측정소 원주시(남한강대교)와 여주시(남한강교) 상·하류 유량자료를 검토·분석하여 하천수 사용허가권에 등재된 하천수 이용량을 검토하고자 한다. 아울러 상·하류 자동유량관측소 내 지류 하천(섬강, 청미천)이 유입되고 있어, 추가 유입량을 고려한 물수지 분석을 위해 원주시(문막교)수위관측소, 여주시(원부교)수위관측소의 유량자료를 이용하였다. 상·하류 유량자료 검토 결과, 지류 유입량 + 하류 여주시(남한강교)) 유량이 상류 원주시(남한강대교) 유량보다 작은 상·하류 유량이 역전('19~'20, 평균 787,753m3/day)되는 흐름이 발생하였다. 구간 내 등재된 취수시설물(11개소) 허가량(39.66×106m3) 보다 실재 사용량은 많을 것으로 추정되며 상·하류 역전 흐름에 직접적인 영향을 준 것으로 판단된다, 또한 현장 조사에서 허가대장에 미등재된 다수의 시설을 발견하였으며 이는 하천수의 효율적인 관리에 장애요인으로 작용된다. 하천수 사용은 복합허가사항으로 홍수통제소에서 사용허가부터 관리까지 실시하고 있는데 하천수 허가 신청량은 계획수요량 산정과 물수지 분석결과를 통하여 적정성 검토가 이루어지고 있다. 그러나 하천수 사용허가량 대비 실제 하천수 취수량이 얼마나 되는지 파악은 불가능한 실정이다. 결국 하천 유량을 관리하기 위해 강수량, 수위, 유량 등 많은 수문요소를 정확하게 측정하는 것도 필요하지만 이처럼 하천수 이용을 위해 취수되는 양을 정확하게 계측하지 않는다면 효율적인 하천수 관리는 어렵다. 하천수를 관리하고 효율적으로 이용하기 위해 하천수 이용에 대한 제도적인 보완이 필요해 보인다.

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Numerical modeling of secondary flow behavior in a meandering channel with submerged vanes (잠긴수제가 설치된 만곡수로에서의 이차류 거동 수치모의)

  • Lee, Jung Seop;Park, Sang Deog;Choi, Cheol Hee;Paik, Joongcheol
    • Journal of Korea Water Resources Association
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    • v.52 no.10
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    • pp.743-752
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    • 2019
  • The flow in the meandering channel is characterized by the spiral motion of secondary currents that typically cause the erosion along the outer bank. Hydraulic structures, such as spur dike and groyne, are commonly installed on the channel bottom near the outer bank to mitigate the strength of secondary currents. This study is to investigate the effects of submerged vanes installed in a $90^{\circ}$ meandering channel on the development of secondary currents through three-dimensional numerical modeling using the hybrid RANS/LES method for turbulence and the volume of fluid method, based on OpenFOAM open source toolbox, for capturing the free surface at the Froude number of 0.43. We employ the second-order-accurate finite volume methods in the space and time for the numerical modeling and compare numerical results with experimental measurements for evaluating the numerical predictions. Numerical results show that the present simulations well reproduce the experimental measurements, in terms of the time-averaged streamwise velocity and secondary velocity vector fields in the bend with submerged vanes. The computed flow fields reveal that the streamwise velocity near the bed along the outer bank at the end section of bend dramatically decrease by one third of mean velocity after the installation of vanes, which support that submerged vanes mitigate the strength of primary secondary flow and are helpful for the channel stability along the outer bank. The flow between the top of vanes and the free surface accelerates and the maximum velocity of free surface flow near the flow impingement along the outer bank increases about 20% due to the installation of submerged vanes. Numerical solutions show the formations of the horseshoe vortices at the front of vanes and the lee wakes behind the vanes, which are responsible for strong local scour around vanes. Additional study on the shapes and arrangement of vanes is required for mitigate the local scour.

A Study on the relationship between Spatial Expression & Emotional Character - based on the psychological healing theory of Marks Lüscher - (공간표현과 감정특성간의 연관성에 관한 연구 - 막스 뤼셔의 심리치유이론을 중심으로 -)

  • Kim, Kwang-Ho
    • Journal of The Korea Institute of Healthcare Architecture
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    • v.11 no.2
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    • pp.63-71
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    • 2005
  • The purpose of this study is to find the complementary idea of the psychological elements in aesthetic expression of architectural space in the sense of healing. Marks $L\ddot{u}scher$, the swiss psychologist suggested reasonable categories of emotional character according to the couple combinations among Content, Self-Esteem, Confidence, and Liberty. His theory on healing is not only the concept but the practical method to understand and control the conflict between contrary elements of emotion. Compared to the Freud's objective theory of cause and consequence, his idea is focused on the subjective and autonomous harmony. This theory based on complementary idea is applied to psychological attitude of architects on Spatial Expression in this study. Refuge, Prospect, Flow and Void are assumed as equivalent spatial elements to the four major emotional conditions suggested by $M.L\ddot{u}scher$. The couple combinations among them also characterize the architectural characters definitely and it is expected to be the reasonable criteria in analysing aesthetic value and motive of creating human space.

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Assessment Models of Political Risk and the Sensitivity Analysis (정치적 위험의 평가모형과 민감도분석)

  • Moon, Chang-Kuen;Yim, Chun-Ho
    • Korean Business Review
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    • v.20 no.1
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    • pp.105-122
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    • 2007
  • This paper identifies the dimensions of political risk on the basis of the classification between risk and uncertainties to implement the precise identification and assessment of the various types of political risk and develop the sound assessment model to accomplish their practical applications. This paper shows the concrete and detailed processes of deriving the assessment models and applying them with the microsoft excel spreadsheet, confirms the result of Butler and Joaquin(1998), and presents the methods of identifying the various combination effects of the political risk impact and the covariance relationship with the market portfolio return through the sensitivity analysis.

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Fuzziness for Buckling Loads of Columns with Uncertain Medums (불확실한 매체를 갖는 기둥 좌굴하중의 애매성)

  • 이병구;오상진
    • Journal of the Korean Institute of Intelligent Systems
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    • v.5 no.2
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    • pp.86-96
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    • 1995
  • In this paper the fuzzy extension for the classical engineering mechanics problems is studied. The governing differential equation is derived for the buckling loads of the columns with uncertain mediums: the their own weight and the flexural rigidity. The columns with one typical end constraint(hinged1 clarnped/free) and the other finite rotational spring with fuzzy constant are considered in numerical examples. The vertex method is used to evaluate the fuzzy functions. The Runge-Kutta method and Determinant Search method are used to solve the differential equation and determine the buckling loads, respectively. The membership functions of the buckling load are calculated. The index of fuzziness to quantitatively describe the propagation of fuzziness is defined. According to the fuzziness of governing factors, the varlation of index of fuzziness for buckling load is investigated, and the sensitivity for the end constraints is analyzed.

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The Characteristic Investigation of the Flowfield around Two Circular Cylinders in Various Arrangements Using the PIV (PIV를 이용한 다양한 배열에서 2원주 주위의 유동장 특성 연구)

  • Ro, Ki-Deok;Kim, Kwang-Seok
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.36 no.2
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    • pp.131-136
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    • 2008
  • The characteristics of the flowfields around two circular cylinders in various arrangements were investigated by PIV. In tandem arrangement, the Strouhal numbers measured in the rear region of the cylinder of wake side were decreased with the space ratios, the flow between two cylinders was almost stagnated and the closer to upstream cylinder, the larger the width of the stagnated region was. The direction of vortex between two cylinders was opposed each other with the small difference(${\alpha}$=${\pm}1.0^{\circ}$) of the attack angle . In side by side arrangement, the flow velocity between two circular cylinders were increased with the space ratios.

Development of Language-Learning Courseware in Korean Environments (한글 환경에서의 언어 교육 시스템 개발)

  • Kim, Hae-Gyung;Yoon, Ae-Sun;Lee, Mi-Hwa
    • Annual Conference on Human and Language Technology
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    • 1998.10c
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    • pp.335-340
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    • 1998
  • 최근 컴퓨터 통신 기술의 발달로 인하여 교육분야에서의 컴퓨터 통신망을 이용한 학습의 효율성 증대에 대한 연구가 활발하다. 지금까지의 학습 방식은 교과목 특성의 개별성을 인식하지 못하거나 혹은 기술적인 문제점 등으로 인하여 학습자들에게 일관된 단답형이나 선다형의 학습 방식을 요구하여 왔다. 웹을 기반으로 한 원격 교육으로의 활용 측면에서 프랑스어와 같은 제2외국어의 경우, 한국어 환경에서의 프랑스어 악상 문자 입력이나 개별화된 저작 언어 개발 등의 문제점이 제기된다. $\lceil$Voila-web$\rfloor$ 은 한국어를 모국어로 하는 프랑스어 학습자들을 위한 교육 시스템으로 개별 교과목의 특성을 반영하고 능동적인 학습 방식을 통한 학습의 효율성 증대를 위한 시스템이다. 학습자들에게는 학습 자료의 전체적인 내용 흐름만을 제시하고 영역별 구체적인 자료의 전개는 다양한 교과 내용을 자유 항해할 수 있도록 설계되어 있다. 이는 학습자들로 하여금 통신망을 통한 컴퓨터 이용 학습의 장점을 기존의 학습 방식에 보완하여 보다 능동적인 학습 방식을 유도하여 학습의 효율성을 증대시킬 수 있다.

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Narrative Structure in "World of Warcraft" ("World of Warcraft"의 서사 연구)

  • Lee, Jae-Hong
    • Journal of Korea Game Society
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    • v.8 no.4
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    • pp.45-53
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    • 2008
  • This paper analyzed the narrative construction of ‘World of Warcraft’ which is very popular worldwide. Narratology and ludology should be interrelated in the larger area of art, rather than existing as separate fields. Dramatic narrative constructions of game would be made when the rules of game emerge with the circumstances of play. This paper reviews how 'World of Warcraft' generates its tremendous popularity through analyzing the overall narratives of 'World of Warcraft' and sub-narratives such as quest, PvP and hunting systems. The distinctive feature of this game is its well-designed story flow which is emerged by both underlying linear original story and non-linear multi-scenario that offers rich interactivities to the game users.

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Wind Tunnel Wall Interference Correction Method for Helicopter Rotor Tests with Closed and open Test Sections (헬리콥터 로터의 폐쇄형 및 개방형 풍동시험 벽면효과 보정기법 연구)

  • Lee, Hyeon-Jung;Jang, Jong-Youn;Lee, Seung-Soo;Kim, Beom-Soo;Song, Keun-Woong
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.36 no.7
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    • pp.621-627
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    • 2008
  • Aerodynamic data measured in a wind tunnel has inevitable errors due to the presence of the wind tunnel walls. These unwanted interference effects must be corrected for the wall interference free aerodynamic data. Streamline curvature effects are caused by straightening of streamlines due to wind tunnel walls. Classical Glauert's correction method that is a standard method for fixed wing aircraft is not suitable for rotary wing aircraft. In this paper, Heyson's correction method of which wake model is compatible with rotors is used to correct the rotor shaft angle as well as the dynamic pressure. The results of Heyson's method are compared with Glauert's correction method.

A Study on the Healing working space through Aesthetic Office Landscape -Focused on the Psychological Healing theory of Max Lṻscher- (감성적 오피스 랜드스케이프를 통한 치유적 사무공간에 관한 연구 -막스 뤼셔의 심리치유이론을 중심으로-)

  • Jin, Dal-Rae;Kim, Kwang-Ho;Kim, Hye-Yeon
    • Journal of The Korea Institute of Healthcare Architecture
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    • v.13 no.3
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    • pp.7-14
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    • 2007
  • The concept and spatial composition of office have endlessly changed according to social trend. And according to social change, members of office, namely, concept of organization has been changed. Presently, our society finds and needs appearance of office suitable for our society. According to a concept of ecological environment and a concept laying stress on human, various trials have been performed but still, stress of salaried men is treated as social issue. By having connection between psychological healing theory of Max $L{\ddot{\bar{u}}}scher$ and spatial expression elements (content : refuge, self-esteem : prospect, confidence : flow, liberty : void) as a theory, we discussed possibility of aesthetic office landscape could be developed to a type of office which could control emotion that can be a cause of stress and we intended to examine limitation and possibility through case analysis.

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