• International Journal of Fluid Machinery and Systems
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• 제6권3호
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• pp.144-151
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• 2013

In this paper, the design method of a low-head propeller-type hydro turbine is studied for various numbers of blades on an axial propeller. We also investigate the relationship between geometrical parameters and internal performance parameters, such as angular velocities (100, 200, 300, 400 rpm) and 2.5~4m low heads through a three-dimensional numerical method with the SST turbulent model. The numerical results showed that the blade number had a more dominant influence than the change in heads and rotational speed on the flow characteristics of the turbine. The distributions of pressure and velocity in the streamwise direction of the propeller turbine were graphically depicted. Especially, the relationship among dimensionless parameters like specific speed ($N_s$), flow coefficient (${\phi}$) and power coefficient (P) were investigated.

• 한국농공학회논문집
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• 제54권1호
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• pp.109-114
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• 2012

Stage-discharge relationship is applied to convert water level into discharge at the auto-measuring station in many irrigation canals. The stage-discharge curve is very important for reliable application for the agricultural water management system. We made results of discharge measurement at 18 stations in the irrigation canal nearby the Idong reservoir from 2010 to 2011. Stage-discharge relationships for each 18 stations were drawn considering of different hydraulic and geometrical characteristics at each stations. R-squared over 0.91 at each stations show high reliability for application of these relationships.

• 한국안광학회지
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• 제7권1호
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• pp.21-23
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• 2002

인위적 근시에서 측정된 시력을 이론적 계산과 비교하였다. 계산은 망막에 형성되는 착란원 뿐만 아니라 상의 높이도 포함시켰다. 착란원은 기하광학적 모델에서 계산하였으며, 망각상의 높이는 인위적 근시에서 측정된 굴절력과 시력과의 관계로 계산하였다. 이 결과를 착란원과 망막상 높이의 비로서 망막상비를 정의하여 시력크기에 대한 망막상비의 관계를 조사하였다.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2003년도 추계학술대회논문집
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• pp.879-884
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• 2003

This paper is to experimentally investigate the effect of the through-flow and grazing-flow on the absorption performance of a perforated plate system. The experiment is performed through the systematic change of the through-flow velocity, grazing-flow velocity, incident sound pressure level, and the geometrical parameters such as the porosity and hole diameter. From the experimental results, it is found that for the nonlinear relationship between the acoustic resistance and incident sound pressure level there is no influence of the through-flow on the absorption performance, but fur the linear relationship between them there is a strong dependence of the absorption performance on the through-flow velocity. It is also shown that the absorption performance is controllable by changing the porosity and hole-diameter in size.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2003년도 춘계학술대회논문집
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• pp.163-167
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• 2003

This paper is to experimentally investigate the effect of the through-flow on the absorption performance of a perforated plate system. The experiment is performed through the systematic change of the through-flow velocity, incident sound pressure level, and the geometrical parameters such as the porosity and hole diameter. From the experimental results, it is found that fur the nonlinear relationship between the acoustic resistance and incident sound pressure level there is no influence of the through-flow on the absorption performance, but for the linear relationship between them there is a strong dependence of the absorption performance on the through-flow velocity. It is also shown that the absorption performance is controllable by changing the porosity and hole-diameter in size.

• 한국강구조학회 논문집
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• 제29권5호
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• pp.341-352
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• 2017

강구조물을 접합하는 대표적인 두 가지 방법으로는 용접접합과 볼트접합이 있다. 이중 잘 접합된 볼트접합은 지압메카니즘에 의한 강도상승과 연성거동을 기대할 수 있다. 이러한 볼트접합부의 연성능력을 충분히 활용하기 위해 본 연구에서는 합리적인 단일볼트접합부의 힘-변형관계 및 지압강도 산정식을 제안하고자 하였다. 볼트접합부의 경계조건 및 기하학적인 요소를 고려하여 체계적으로 단일볼트 실험을 수행하였다. 현행 설계기준의 볼트접합부의 지압강도 산정식의 모순점을 해결하기 위해 새로운 지압강도 설계식 및 변형한계 산정식을 제안하였다. 또한 접합부의 강성, 강도, 기하학적 조건 등을 반영할 수 있는 힘-변형관계식을 제안하였다. 본 연구에서 제시한 지압강도식 및 힘-변형관계식은 현행설계기준보다 합리적으로 실험결과를 예측하였다.

• 대한수학교육학회지:학교수학
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• 제18권1호
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• pp.1-14
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• 2016

본 논문에서는 우리나라 초등학교 수학 교과서에서 취급하는 내용의 범위를 명확하게 정하기 위한 토대를 마련하기 위해, 현행 교과서에서 취급하는 내용과 관련한 문제점을 분석하고 있다. 먼저 교육과정과의 불일치라는 의미에서 쟁점이 될 수 있는 것으로 퍼센트포인트, 오목다각형, 사건이 일어날 가능성의 취급에 관해 논의하고 있다. 다음으로 일상생활에서 사용하는 방식과의 간격이라는 의미에서 쟁점이 될 수 있는 것으로 이산량 단위를 붙인 분수와 '배'를 붙인 분수의 취급에 관해 논의하고 있다. 마지막으로 논리적인 비약이라는 의미에서 쟁점이 될 수 있는 것으로, 자연수를 분수로 나타내기와 도형의 위치 관계의 취급에 관해 논의하고 있다. 그리고 이러한 논의 결과로부터 얻은 다음 시사점 세 가지를 결론으로 제시하고 있다. 첫째, 교과서와 교육과정의 관계를 명확히 설정할 필요가 있다. 둘째, 교과서에서 개념을 정의 또는 취급하는 방식과 일상생활에서 그 개념을 사용하는 방식의 혼용에 유의할 필요가 있다. 셋째, 교과서에서 논리적 비약을 확인하고 그것을 해소할 필요가 있다.

• 한국실내디자인학회논문집
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• 제13권3호
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• pp.153-161
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• 2004

Organic Modernism was inaugurated by Alvar Valto as an alternative plan to the formative limitation of Geometrical Modernism. It began to appear in the 1930s in the fields of Architecture, Furniture, Product Design and so on. It is known that began with organic formative language is closely related to surrealistic artists Andre Breton as well as other artists and sculptors in that era. Such Formative Language formalized a stream of Organic Modernism Furniture Design unique to the regional and cultural characteristics of Scandinavia. After crossing over to America, mass production of Furniture was born and new materials were linked by industrialization. The Characteristics of Organic Formation in Modern Art such as Three -Dimensional, Biological Morphological, Symbolical, Primitive, Fantastical, Non-Realistic, Incidental, Irregular, transmit to Furniture Design. They are as Characteristics especially with Three-Dimensional, Biological Morphological and Symbolical aspects. Histories of Art and design, there are some examples showing mutual Interchange between Functional and Artistic Character. This thesis also clarifies the Formative Relationship that the Furniture designers who pursued Functionality and Mass Production had obtained from Modern Artistic works and the Artists, through the process of comparing and researching the typical Artists and their works.

• 감성과학
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• 제5권3호
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• pp.1-10
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• 2002

This paper concerns with the relationship between the visual perception of the degree of pucker or wrinkles of garment surfaces and the geometrical parameters of surfaces. In this study, four potentially relevant parameters of the surface profile are considered, namely, the variance ($\sigma$$^2$), the cutting frequency (F$\_$c/), the effective disparity curvature (D$\_$ce/) (Defined as the average disparity curvature of the wrinkled surface over the eyeball distance of the observer) and the frequency component of the disparity curvature ( D$\_$cf/). Based on the experiments using garment seams having varying degree of pucker (i.e. the wrinkles along a seam line), it was found that, while the logarithm of each of these four parameters has a strong linear relationship with the visually perceived degree of wrinkles, following the Web-Fetchner Law, the effective disparity curvature ( D$\_$ce/) and the frequency component of the disparity curvature (D$\_$cf/) appeared to have stronger relationships with the visual perception. This finding is in agreement with the suggestion by Rogers '||'&'||' Cagenello that human visual system may compute the disparity curvature in discriminating curved surfaces. It also suggested an objective method of measuring the degree of surface wrinkles.

• 한국실내디자인학회논문집
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• 제16권6호
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• pp.11-18
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• 2007

Edward Hopper is one of the great American artists in the 20th Century. In the field of art, it seems that his paintings are thoroughly analyzed In terms of human alienation and emotional aspects in various ways. However, in his numerous paintings, highly interesting spatial aspects can be found. Purpose of this study is to analyze some of his painting by the spatially analytical tools to examine how his space is experienced. The tools are: relationship between each space, relationship between light and space, and geometrical composition. Among many paintings by Hopper, four of the works that depicted interior spaces are selected and further case-studied in detail: ${\ulcorner}$Rooms by the Sea${\lrcorner}$ (1951), ${\ulcorner}$Sun in an Empty Room${\lrcorner}$ (1963), ${\ulcorner}$New York Movie${\lrcorner}$ (1939) and ${\ulcorner}$Automat${\lrcorner}$ (1927). An Environmental Simulation with scale models was used to examine the relation between light and space. After the research, some unique characteristics of his space were found. Even though his paintings seem to represent the everyday spaces, there are fascinating hidden structure to make people experience in a specific way that Hopper created. Spaces In his paintings do not communicate with each other but are constantly interrupted by the element of time. The mundane everyday world is rediscovered and recreated through these multidimensional and heterogeneous space.