• 제목/요약/키워드: Focusing Element

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Element Free Galerkin Method applying Penalty Function Method

  • Choi, Yoo Jin;Kim, Seung Jo
    • Journal of the Korean Society for Industrial and Applied Mathematics
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    • v.1 no.1
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    • pp.1-34
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    • 1997
  • In this study, various available meshless methods are briefly reviewed and the connection among them is investigated. The objective of meshless methods is to eliminate some difficulties which are originated from reliance on a mesh by constructing the approximation entirely in terms of nodes. Especially, focusing on Element Free Galerkin Method(EFGM) based on moving least square interpolants(MLSI), a new implementation is developed based on a variational principle with penalty function method were used to enforce the essential boundary condition. In addition, the weighted orthogonal basis functions are constructed to overcome disadvantage of MLSI.

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Squint-less Phased Array Antenna Near-field Subwavelength Focusing with True-time Optical Delay Line (광 지연선로를 이용한 스퀸팅이 없는 위상배열 안테나의 근접장 서브파장 포커싱)

  • Jung, Young Jin
    • Korean Journal of Optics and Photonics
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    • v.30 no.3
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    • pp.94-100
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    • 2019
  • The near-field subwavelength squint-less focusing system of a phased array antenna is designed and demonstrated by numerical simulation. The Huygens-Fresnel principle is applied to numerical simulation for calculation of the phased array antenna at microwave frequency. It was shown that beam squinting can be eliminated, utilizing true-time optical delay lines based on a chirped fiber grating in the proposed system. Furthermore, subwavelength focusing with high numerical aperture can be achieved by considering the fact that the array elements of the phased-array antenna can be treated as diffractive elements in an optical lens system. Also, side lobes can be suppressed by decreasing the distance between element antennas to less than half of the wavelength.

A Study on the Characteristics of Transferred Element in Composition of Architectural Spaces -Focusing on Path and Stairs (공간구성에 있어서 전이적 요소의 특성에 관한 연구 -통로와 계단을 중심으로 -)

  • 이승우;윤도근
    • Korean Institute of Interior Design Journal
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    • no.7
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    • pp.79-86
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    • 1996
  • This study is searching the characteristics of transferred element in composition of architectural spaces ; it is ultimate goal that frame of reference is arranged system about path of horizontal direction is two-dimension and stairs of vertical in three-dimension as transferred element in Architectural plan. With the exception of stylized discussion or rhetorical analysis about these, it is analysed as element in physical order of a whole architecture in relation to another elements in composition of architecture spaces. And one who is perceptible and cognitive through spaces is the subject. Consequently , these elements are classified concept of location and circulation. And it can't think that the formal is divided the latter for accept behavior of pedestrican and thinking system to consider verticality and time property is absolutely conceptual elements in space of architectural plan.

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Research on Improvement of Performance of Anemometer Using PTC Thermistor (PTC 서미스터를 이용한 유속계의 성능향상에 관한 연구)

  • Yoon, Joon-Yong;Cho, Nahm-Gyoo;Kim, Jin-Rae;Sung, Nak-Won;Kim, Hwang-Jin
    • The KSFM Journal of Fluid Machinery
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    • v.3 no.4 s.9
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    • pp.15-21
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    • 2000
  • An anemometer employing the bulk PTC thermistor as the sensing element is investigated in this study. The numerical and experimental works are carried out to improve the sensitivity problem of the element by focusing fluid dynamics point of view. The typical shape of the sensing element has been used as a rectangular type, but this shape has a sensitivity problem because of flow separations on the sharp edge when the flow direction is different from that of the sensing element. In order to reduce the reading error, the installer has to be very careful about the flow direction. The reading error fluctuation by time as well as the sensitivity problem can be improved considerably through this study. It can be concluded that the small change of the sensor shape can improve the performance of the flow sensor.

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Optimization of Round Bar Forging Process by Using Finite Element Analysis (유한요소해석을 이용한 환봉 단조공정 최적화)

  • 최성기;천명식;문영훈
    • Transactions of Materials Processing
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    • v.13 no.2
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    • pp.142-147
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    • 2004
  • Three-dimensional rigid-plastic finite element analysis has been performed to optimize open die forging process to make round bar. In the round bar forging, it is difficult to optimize process parameters in the operational environments. Therefore in this study, finite element method is used to analyze the practice of open die forging, focusing on the effects of reduction, feeding pitch and rotation angle for optimal forging pass designs. The soundness of forging process has been estimated by the smoothness and roundness of the bar at various combination of feeding pitches and rotation angles. From the test result, process conditions to make round bar having precise dimensional accuracy have been proposed.

A Study on Vibration Analysis Method Using the Global Structural Analysis Model (전선 구조해석 모델을 이용한 진동해석 방법에 관한 연구)

  • Park, Hyung-Sik;Choi, Su-Hyun;Lee, Yong-Sub
    • Journal of the Society of Naval Architects of Korea
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    • v.44 no.3 s.153
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    • pp.314-322
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    • 2007
  • In general, the vibration and structural analyses have been carried out by using each finite element model separately because of different size of finite element mesh and different focusing area of each analysis. In some cases, however, it is required to perform both global vibration and structural analyses at the same time using a finite element model for global structural analysis, which asks for a special treatment for a vibration analysis. In this study, a technique to perform a global vibration analysis using a finite element model for a global structural analysis has been developed and its effectiveness has been verified by its application to a whole ship.

A Case Study on the Low Carbon Green Housing Complex, U.K. - Focusing on the Design Elements of ZEDfactory - (영국의 저탄소 녹색 주거단지 사례에 관한 연구 - 영국 ZEDfactory의 설계요소를 중심으로 -)

  • Moon, Sun-Ki;Kim, Sei-Yong;Kim, Ji-Yun;Park, Geun-Chul
    • Proceeding of Spring/Autumn Annual Conference of KHA
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    • 2011.04a
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    • pp.127-132
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    • 2011
  • The purpose of this study was to search the cases of low carbon green housing complex specially focusing on the design elements of ZEDfactory in UK and find the suggestion for the low carbon green housing complex in Korea. For this purpose, we reviewed the design elements of low carbon green housing, which are created by ZEDfactory. We also analyzed the 4 cases of them focusing on the design elements and synthesized the elements. As a result of this study, we can draw some implications and ways to apply the low carbon green concepts for housing complex such as the thermal heating, cooling and microgeneration solution using available renewable energy.

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The Change of 'Attention Resources' and 'Space-Memory' by Lighting focusing on 'Selective Attention (선택적 주의 관점에서 본 조명에 의한 주의 자원과 공간 기억의 변화)

  • Seo, Ji-Eun
    • Korean Institute of Interior Design Journal
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    • v.25 no.2
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    • pp.41-49
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    • 2016
  • The purpose of this study is to analyze the change and to compare to the difference of 'selective elements' and 'space-memory' focusing on the theory, 'selective attention' through the survey results. In this study, In this study, the lighting is considered a important factor in the change of 'selective elements'. this survey is to find the selective elements of participants and to measure the spatial sensitivity of respondents through 'self- test'. The analysis in this study is conducted by descriptive statistics, t-test and one way ANOVA by SPSS program 22. The results of this study are as following; Firstly, 'attention-element' could be classified with 4 types, 'shape', 'material', 'contrast' and 'combination'. 'shape' could divide into 'structure' and' furniture and object'. In case of 'material', it could section with 'pattern' and 'color'. Secondly, through the results of study, 'attention-element' is different each space during the day in detail. But we could know that 'shape' is the important element of the 'attention-elements' during the day through comparison of this result. That means users consider this as a important factor when they evaluate the space. Therefore, it is effective way designers to consider 'shape' as the first element when they want to conduct the special sensitivity of users in the space through planning. On the other hand, what selective elements of users are different by the lighting situation should be acknowledged by designers. And they should think the kinds of selective elements are more various when lighting turns on than turns off.. Thirdly, through the results such as the meaningful difference of space-memory of users according to the change of 'attention-elements', designers should judge about which kind of feeling of users to the space do you want lead in the design process. For the effective feedback between spaces and users to induce the same emotion of users, designers need to consider the unified design and the individual design both. Also, we will regard the differences in the users' emotion to the space according to the lighting situation when we design the space.

Design of a Submerged Coastal Structure for Concentration of Wave Energy and Control of a Coastal Area (파랑에너지 집적 및 연안해역 제어를 위한 해저구조물의 설계)

  • Lee, J.W.;Krock, H.J.
    • Journal of Korean Port Research
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    • v.8 no.2
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    • pp.37-56
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    • 1994
  • The effects of wave energy focusing by a submerged berm type of structure is examined. The fundamental idea is based on the phenomenon of refraction by a lens-shaped crescent structure which results in the focusing of wave energy on the center line of the structure. The shape of the submerged structure is a complex curve combining circular with elliptical elements. Based on the design procedure, a special configuration of structure(termed herein as a triple crescent structure) is introduced. Next, some hydraulic model tests are performed to confirm the wave focusing effect in laboratory. In addition, in order to interpret the wave focusing performance behind the structure, a numerical procedure by the hybrid element method is used on the basis of the conventional mild slope equation but modified and extended to allow for steeper bottom slopes and higher curvature. The modified refraction and diffraction provide additional mechanism for wave height amplification and the maximum amplification for triple crescent structure is presented. It also allows for the possibility of wave energy scattering with the change of the incident wave direction. Comparisons with previous theoretical results involving a submerged crescent shape structure are described.

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