• Title/Summary/Keyword: Modeling step

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Computing turbulent far-wake development behind a wind turbine with and without swirl

  • Hu, Yingying;Parameswaran, Siva;Tan, Jiannan;Dharmarathne, Suranga;Marathe, Neha;Chen, Zixi;Grife, Ronald;Swift, Andrew
    • Wind and Structures
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    • v.15 no.1
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    • pp.17-26
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    • 2012
  • Modeling swirling wakes is of considerable interest to wind farm designers. The present work is an attempt to develop a computational tool to understand free, far-wake development behind a single rotating wind turbine. Besides the standard momentum and continuity equations from the boundary layer theory in two dimensions, an additional equation for the conservation of angular momentum is introduced to study axisymmetric swirl effects on wake growth. Turbulence is simulated with two options: the standard ${\kappa}-{\varepsilon}$ model and the Reynolds Stress transport model. A finite volume method is used to discretize the governing equations for mean flow and turbulence quantities. A marching algorithm of expanding grids is employed to enclose the growing far-wake and to solve the equations implicitly at every axial step. Axisymmetric far-wakes with/without swirl are studied at different Reynolds numbers and swirl numbers. Wake characteristics such as wake width, half radius, velocity profiles and pressure profiles are computed. Compared with the results obtained under similar flow conditions using the computational software, FLUENT, this far-wake model shows simplicity with acceptable accuracy, covering large wake regions in far-wake study.

Microstructural Analysis of Thermo-Mechanical Processed Ti-6Al-4Fe Alloy (Ti-6Al-4Fe 합금의 가공열처리 미세조직 분석)

  • Choe, Byung Hak;Choi, Won-Youl;Shim, Jong Heon;Park, Chan Hee;Kang, Joo-Hee;Kim, Seung Eon;Hyun, Yong Taek
    • Korean Journal of Materials Research
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    • v.25 no.8
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    • pp.410-416
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    • 2015
  • Microstructural analysis of a (${\alpha}+{\beta}$) Ti alloy was investigated to consider phase transformation in each step of the thermo-mechanical process using by SEM and TEM EDS. The TAF (Ti-6Al-4Fe) alloy was thermo-mechanically treated with solid solution at $880^{\circ}C$, rolling at $880^{\circ}C$ and annealing at $800^{\circ}C$. In the STQ state, the TAF microstructure was composed of a normal hcp ${\alpha}$ and metastable ${\beta}$ phase. In a rolled state, it was composed of fine B2 precipitates in an ${\alpha}$ phase, which had high Fe segregation and a coherent relationship with the ${\beta}$ matrix. Finally, in the annealing state, the fine B2 precipitates had disappeared in the ${\alpha}$ phase and had gone to the boundary of the ${\alpha}$ and ${\beta}$ phase. On the other hand, in a lower rolling temperature of $704^{\circ}C$, the B2 precipitates were more coarse in both the ${\alpha}$ and the boundary of ${\alpha}$ and ${\beta}$ phase. We concluded that microstructural change affects the mechanical properties of formability including rolling defects and cracks.

A study on the Color Analysis to he a Beautiful Face Conference Work - Focused on a Work of the Competition After 1980 - (미용대회 작품헤어 컬러분석 - 1980년대 이후 대회작품을 중심으로 -)

  • You, Ok-Lee;Paik, Sun-Young
    • Journal of the Korean Society of Fashion and Beauty
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    • v.5 no.4
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    • pp.149-157
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    • 2007
  • Hair style was mean of visual symbol that display position or wealth about human life. Also, have spoken for cultural value as human body plastic art that speak for the age. I wished to study about modeling of hair style and interrelationship of color by analyzing systematically laying stress on color through contest creation work consisted in beauty art congress. Urpose of this study is as following. First, examines domestic' outside great council work head change by era, and studies Hair Work's change in work head. Second, Hair Color's change that appear in domestic' outside contest work head studies effect that get in work. Method of study runs parallel literature study and supporting research, utilized domestic' outside literature, connection paper, magazine, picture data etc. To literature study, and work picture data examined laying stress on work that is choosesed picture dataworld beauty use association (OMC) data etc. that appear in domestic' outside beauty art magazine to examine closely specification and stability of beauty art game style and participates in domestic and world beauty art contest. In this study, domestic' characteristic, and effect that collar gets in work head of collar that collects outside contest participating in an athletic contest hair style by ($1981{\sim}$until present) by year and appears in contest work head and in work since analyzing study forward $2007{\sim}2008$ year direction of collar. First, stream of whole color of the 1980s Brown gave highlight color point partially to basis, and was consisted of creative style and do Gold base color on the whole in Hair by Night item. Second, various Hair color was popularized in the 199Os, and Tuton's color appeared in beauty art game work, and I contributed to improve technique that step-up gradation color appears and does technique to highlight in neon orange in creative style and Hair by Night item by entrance on the stage of neuter gender color.

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The Development of the Object Oriented Simulator of the Container Terminal (컨테이너 터미널 시뮬레이터의 객체지향 설계)

  • Yun, Won-Young;Ryu, Sook-Jea;Kim, Gui-Rae;Kim, Do-Hyung;Choi, Yung-Suk
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • v.1
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    • pp.325-330
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    • 2006
  • The container terminal is the unified transportation system which connects between a land transportation and a sea transportation. This system has many subsystems such as ship operation, yard transfer operation, yard storage system, gate operation, and information manage system. This paper presents a method of modeling a simulator with which user can evaluate the efficiency of the equipment and allocation policies in the container terminal. The final purpose is to estimate the efficiency of each equipments and the distribution policies. In a design step in the simulator development. We suggest the Object Oriented method with which the developer can easily design, because the object oriented method has the advantages of reusability and modularity.

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Character modeling using ZSphere (ZSphere를 활용한 캐릭터모델링)

  • Ryu, Chang-Su;Hur, Chang-Wu
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2011.10a
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    • pp.524-526
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    • 2011
  • ZSphere of ZBrush can be added to the screen, and most of all, added to the existing ZSphere as mobile geometrical objects. For example, legs can be produced out of the globoid in the progress of an intermediate step. characters with multiple limbs can be produced easily in this way. With Zsphere, several Child Spheres can be produced out of single Sphere, then these can be parents spheres, and can connect other Child Spheres. In this paper, by making each form through these processes, 3D characters were modeled to shape easily and rapidly. Since 3D objects can be added, rotated, and moved, they can interact smoothly with Z-depth of campus. To place these objects on the screen, paint, build fixed perspective image, smerge pixols and transform 3D objects, diverse transforming tools and sculpturing tools were used. The characters were designed in the way that first, the finished 3D characters were transformed into poly, then each side was restructured rapidly with Topology.

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A Design of Development Process Model of Product Lines for Developing Embedded Software (임베디드 소프트웨어 개발을 위한 제품계열 중심의 개발프로세스 모델 설계)

  • Hong, Ki-Sam;Yoon, Hee-Byung
    • Journal of KIISE:Software and Applications
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    • v.33 no.11
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    • pp.915-922
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    • 2006
  • Recently, the requirements of the embedded software are getting diverse as the diversity of embedded software application fields increases. The systematic development methods are issued to deal with the dependency between hardware and software. However, the existing development methods have not considered the software's close connection to hardware and the high-level reusability for common requirements of several similar domains. In this paper, we propose a design method of development process model of product lines to support an efficient development method for embedded software. For this, we firstly suggest a domain scoping method and an IDEF0(Integration DEFinition)-based business model for extracting the efficient requirements. Next, we present a component deriving method based on the service architecture and an architecture design method after considering the hardware dependency. And we explain the artifacts of MSDFS(Multi Sensor Data Fusion System) at each design step in order to show how the proposed model can be applied to the embedded software development.

A Simplified Model for Compliance Determination of the Moving-Actuator Type Totally Implantable Artificial Heart

  • Park, S.K.;Choi, W.W.;Ahn, J.M.;Kim, S.J.;Choi, J.S.;Jo, Y.H.;Om, K.S.;Lee, J.J.;Kim, H.C.;Choi, M.J.;Min, B.G.
    • Proceedings of the KOSOMBE Conference
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    • v.1996 no.05
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    • pp.82-83
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    • 1996
  • In this paper, we present a simplified model for complicance determination of the moving-actuator type totally implantable artificial heart (TAH). The modeling equations are derived from the mechanics and geometry of the TAH components. The interventricular pressure and volume are computed for determining the compliance of the interventricular space using this model. The model is capable of generating realistic hemodynamic variables such as the left atrial pressure and interventricular pressure and is proved to be acceptable. This model can be used as an initial step for analyzing characteristics of the moving-actuator type TAH.

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A Suppression of Residual Vibration on the Flexible Structures by Input Shaping (입력설계기법에 의한 유연구조물의 잔류진동제어)

  • Park, Myoungho;Han, Myoungseok;Park, Sungjong
    • 대한공업교육학회지
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    • v.31 no.2
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    • pp.364-380
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    • 2006
  • This paper presents a procedure for designing command to maneuver flexible structure with very little residual vibration, even in the presence of modeling errors. For the open loop maneuver, the various shaped profiles using multiple step inputs delayed in time are considered for robustness and compared with the responses of rigid body and flexible body in virtue of simulations and experiments. Input shaping generates vibration-reducing shaped commands through convolution of an impulse sequence with the desired command. A flexible model with a cylindrical hub and four symmetric appendages is considered to examine the responses to real plant, and to illustrate the effectiveness of the proposed shapers. The appendages are long and flexible, leading to low frequency vibration under any control action. It is shown by a series of simulation that a properly designed feedback controller with input shaper performs well, as compared with open loop controller with input shaper. The control objective is to achieve a fast settling time of residual vibration to flexible structure and robustness (insensitivity)to plant uncertainty, to eliminate residual vibration.

Design and Implementation of Generation System for Storing Core Components (핵심 컴포넌트 저장을 위한 시스템 설계 및 구현)

  • Hwang, Jeong-Hee;Kim, Young-Gyun;Ryu, Keun-Ho
    • The KIPS Transactions:PartD
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    • v.11D no.2
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    • pp.361-370
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    • 2004
  • ebXML(Electronic Business using extensible Markup Language) is an XML based new international standard framework of the electronic business. Interoperability among mutually different industry fields can be realized by reusing core component, as a infrastructure of data. For this interoperability, it is needed to define the concrete concept of core component, through analyzing the role and applicability of the core component in business process which defines the interoperability among different companies. Therefore, in this paper, we Inquire the role of the core component in the ebXML, and implement the core component storage system which generates core component to register in registry/repository. The designed system for storing the core component generates suitable core component structure to register in registry/repositor), which can be used to generate new business information entity in a modeling step of business process.

A Preliminary Study of Enhanced Predictability of Non-Parametric Geostatistical Simulation through History Matching Technique (히스토리매칭 기법을 이용한 비모수 지구통계 모사 예측성능 향상 예비연구)

  • Jeong, Jina;Paudyal, Pradeep;Park, Eungyu
    • Journal of Soil and Groundwater Environment
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    • v.17 no.5
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    • pp.56-67
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    • 2012
  • In the present study, an enhanced subsurface prediction algorithm based on a non-parametric geostatistical model and a history matching technique through Gibbs sampler is developed and the iterative prediction improvement procedure is proposed. The developed model is applied to a simple two-dimensional synthetic case where domain is composed of three different hydrogeologic media with $500m{\times}40m$ scale. In the application, it is assumed that there are 4 independent pumping tests performed at different vertical interval and the history curves are acquired through numerical modeling. With two hypothetical borehole information and pumping test data, the proposed prediction model is applied iteratively and continuous improvements of the predictions with reduced uncertainties of the media distribution are observed. From the results and the qualitative/quantitative analysis, it is concluded that the proposed model is good for the subsurface prediction improvements where the history data is available as a supportive information. Once the proposed model be a matured technique, it is believed that the model can be applied to many groundwater, geothermal, gas and oil problems with conventional fluid flow simulators. However, the overall development is still in its preliminary step and further considerations needs to be incorporated to be a viable and practical prediction technique including multi-dimensional verifications, global optimization, etc. which have not been resolved in the present study.