• Title/Summary/Keyword: freeform

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A Study on Evaluation Index of the Panelizing Optimization for Architectural Freeform Surfaces (비정형 파라메트릭 건축부재형성 및 BIM 데이터 변환 프로세스 모델에 관한 연구)

  • Ryu, Jeong-Won
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.18 no.1
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    • pp.287-294
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    • 2017
  • BIM technology has been used in the domestic AEC field since the middle 2000s. BIM has proved its worth in cutting-edge buildings, mega-buildings and freeform buildings in particular. Many freeform buildings could not be completed due to the low level of construction technique. However, many successful cases emerged after adopting digital technology, including BIM which encouraged architects to challenge freeform designs. The modeling software that can generate the freeform shape are not usually able to build the efficient BIM data type in the AEC industry. In this study a process model of the parametric freeform construction member generation and conversion to BIM data is shown and the prototype system is demonstrated.

Design Method for a Total Internal Reflection LED Lens with Double Freeform Surfaces for Narrow and Uniform Illumination

  • Yang, Jae Suk;Park, Jae-Hyeung;O, Beom-Hoan;Park, Se-Geun;Lee, Seung Gol
    • Journal of the Optical Society of Korea
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    • v.20 no.5
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    • pp.614-622
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    • 2016
  • In this paper, we propose a novel differential equation method for designing a total internal reflection (TIR) LED lens with double freeform surfaces. A complete set of simultaneous differential equations for the method is derived from the condition for minimizing the Fresnel loss, illumination models, Snell’s Law of ray propagation, and a new constraint on the incident angle of a ray on the light-exiting surface of the lens. The last constraint is essential to complete the set of simultaneous differential equations. By adopting the TIR structure and applying the condition for minimizing the Fresnel loss, it is expected that the proposed TIR LED lens can have a high luminous flux efficiency, even though its beam-spread angle is narrow. To validate the proposed method, three TIR LED lenses with beam-spread angles of less than 22.6° have been designed, and their performances evaluated by ray tracing. Their luminous flux efficiencies could be obviously increased by at least 35% and 5%, compared to conventional LED lenses with a single freeform surface and with double freeform surfaces, respectively.

A Study on Classification of the Panelizing for Architectural Freeform Surfaces and the Optimization of Panelizing (비정형 건축곡면 패널분할과 최적화 유형 분류에 관한 연구)

  • Ryu, Jeong-Won;Moon, JunSik
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.14 no.9
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    • pp.4616-4626
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    • 2013
  • Freeform buildings have become the main trend that reflects complex and diverse nature of the society with the progress on the digital technology. Therefore, the demands of the researches about architectural freeform surfaces have increased rapidly over the past few years. As the fundamental research for the successful construction of the freeform buildings, this study focuses on the definition of terms, and the classification of curved-form, the methods of panelizing, and the optimization of panelizing through an integrated perspective.

PC-based Controller for Industrial Solid Freeform Fabrication System (산업용 SFFS (Solid Freeform Fabrication System)을 위한 PC 기반 제어기)

  • 박남수;황면중;이두용
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2004.10a
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    • pp.73-77
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    • 2004
  • This paper presents a PC-based controller of industrial SFFS(Solid Freeform Fabrication System). The SFFS has multiple sub-controllers for the building room, the powder room, the temperature, and the density of oxygen in the chambers. Hence the main PC-based controller should effectively and timely send commands to the sub-controllers, and monitor the overall SLS process. The required actuators and sensors are selected to optimize the overall performance of the SFFS.

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Generation of freeform Surface using Measured Data on the Machine Tool (공작기계상에서의 측정데이터를 이용한 자유곡면 생성)

  • 이세복
    • Proceedings of the Korean Society of Machine Tool Engineers Conference
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    • 1998.10a
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    • pp.13-18
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    • 1998
  • The assessment of machined surface is difficult because the freeform surface must be evaluated by surface fairness as well as dimensional accuracy. In this paper, the methodology of freeform surface generation using measured data on the machine tool is presented. The reliability of measured points data is obtained by measuring error compensation. The compensated data are formulated through Non-uniform G-spline surface modeling. In order to improve the surface fairness, the generated model si smoothened by parameterization The validity and usefulness of the proposed method are examined through computer simulation and experiments on the machine tool.

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A Development of Constant-Speed Position Controller for Solid Freeform Fabrication System (임의형상가공시스템을 위한 정속위치제어기 개발)

  • 고민국;김승우
    • Proceedings of the IEEK Conference
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    • 2002.06e
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    • pp.91-94
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    • 2002
  • SFFS(Solid Freeform Fabrication System) is commercializing to rapid prototyping concept in foreign some corporations including the U.S.A, have much technological problems yet and need new mode for agile prototyping. In this paper, we design algorithm that the cutting path of laser beam, on the SFFS(Solid Freeform Fabrication System), is controlled with constant speed. The designed algorithm for constant-speed path control is implemented and experimented in the CAFL$\^$VM/ (Computer Aided Fabrication of Lamination for Various Material) system, the new SFFS which was developed in this paper.

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Process Optimization of Industrial Solid Freeform Fabrication System (산업용 임의형상제작(Solid Freeform Fabrication)시스템의 공정변수 최적화)

  • Kwak, Sung-Jo;Lee, Doo-Yong
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.32 no.7
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    • pp.602-609
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    • 2008
  • This paper presents experimental optimization of process parameters for a newly developed SFF(Solid Freeform Fabrication) system. Two critical process parameters, layering thickness and curing period, which have a large effect on the quality of the product, are optimized through experiments. Specimens are produced using layering thicknesses of 60, 80, 100, 120, 140, and $160\;{\mu}m$ and curing periods of 0, 10, 20, and 30 minutes under the same processing conditions, i.e., build-room temperature, feed-room temperature, roller speed, laser power, scan speed, and scan spacing. The specimens are tested to compare and analyze performance indices such as thickness accuracy, flatness, stress-strain characteristics, and porosity. The experimental result indicates that layering thickness of $80{\sim}100\;{\mu}m$ and curing period of $20{\sim}30$ minutes are recommended for the developed industrial SFF system.

Digital Technologies for Freeform Building in Korea (국내 비정형건축의 디지털 기술적용에 관한 연구)

  • Ryu, Jeong-Won
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.13 no.9
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    • pp.4259-4265
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    • 2012
  • Digital technologies and raising problems in freeform building design and construction in Korea were examined in this paper. Three Korean building cases were researched by having interviews with experts and documentary survey for this purpose. The following problems and important points were drawn from this research. The necessity of panel optimization, significance of the secure file conversion, difficulties in securing constructability of freeform building and using of 3D data for manufacturing panels.

Gaussian Decomposition Method in Designing a Freeform Lens for an LED Fishing/Working Lamp

  • Nguyen, Anh Q.D.;Nguyen, Vinh H.;Lee, Hsiao-Yi
    • Current Optics and Photonics
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    • v.1 no.3
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    • pp.233-238
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    • 2017
  • In this paper we propose a freeform secondary lens for an LED fishing/working lamp (LFWL). This innovative LED lamp is used to replace the traditional HID fishing lamp, to satisfy the lighting demands of fishing and the on-board activities on fishing boats. To realize the freeform lens's geometry, Gaussian decomposition is involved in our optics-design process for approaching the targeted light intensity distribution curve (LIDC) of the LFWL lens. The simulated results show that the illumination on the deck, on the sea's surface, and underwater shows only small differences between LED fishing/working lamps and HID fishing lamps. Meanwhile, a lighting efficiency of 91% with just one third of the power consumption can be achieved, when the proposed LED fishing/working lamps are used instead of HID fishing lamps.

A Fundamental Study on the Comparison of As-Planned with As-Built of Free-form Building Skins Using Laser Scanning Technology (Laser Scanning 기술을 이용한 비정형 건축외피의 As-Planned와 As-Built 비교에 관한 기초적 연구)

  • Kwen, Soon-Ho;Shim, Hyoun-Woo;Jang, Hyoun-Seung;Ock, Jong-Ho
    • Korean Journal of Computational Design and Engineering
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    • v.16 no.2
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    • pp.126-136
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    • 2011
  • The existing approaches to freeform building construction cause many problems. However, recent BIM technique development based on parametric modeling method and improvement of freeform materials manufacturing technology using IT technology encouraged many advanced countries to try experimental projects. Thus, laser scanning technique is in the limelight as a new alternative in the field of freeform building construction and inspection. This study selected a domestic small freeform building and practiced laser scanning and as-planned modeling by using Reverse Engineering. Then each deviation was comparatively analyzed through figures which extracted data by numerically analyzing the newly modeled as-built and Excel spread sheet. Through the process, limits and follow-up research subjects are discussed as well.