• Title/Summary/Keyword: Base Configuration

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THE COMPARISON OF PIFS AND HEAT TRANSFER WITH BASE CONFIGURATIONS (기저 형상에 따른 PIFS 및 열전달 비교 연구)

  • Kim, J.G.;Lee, J.W.;Kim, K.H.
    • 한국전산유체공학회:학술대회논문집
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    • 2010.05a
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    • pp.195-200
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    • 2010
  • Numerical investigation was conducted to study the effects of after-body configurations and nozzle lip on the PIFS(Plume Induced Flow Separation) and eat flux to the base face. Two dimensional and axi-symmetric non-equilibrium Navier-Stoke's solver with $k-{\omega}$ SST turbulence model was used to solve the launching vehicle type configuration with propulsive jet. The experimental result of Robert J. McGhee was compared with our computational results for code validation. Three types of the after-body configurations (Straight, Boat-tail, Flare type) were simulated for this study. And the nozzle lip effect was studies using the three types of base configurations same simulation conditions. As a result of numerical investigations, higher pressure ratio condition and boat-tail after-body configuration caused severe PIFS phenomenon but the flare type after-body configuration and low pressure ratio suppressed PIFS. Flare type after-body configuration and low pressure ratio case reduced heat flux to base face. The nozzle lip dispersed the heat flux widely along the base face and the nozzle lip.

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Optimization of base stations' configuration in UWB-based indoor localization (UWB를 이용한 실내측위의 베이스 스테이션 최적 배치)

  • Chang Ho-Wook;Cha Maeng-Q.;Kim Yong-Il;Yu Ki-Yun
    • Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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    • 2006.04a
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    • pp.3-7
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    • 2006
  • Indoor localization is getting more and more importance with the increasing demand for location based service. Location based service necessarily requires the information about customers' locations to provide them the right service according to their changing locations. To satisfy that requirement, GPS is used to achieve outdoor localization. However, there is no leading technology to achieve indoor localization. Indoor localization through UWB wave and TDOA algorithm is considered as the most accurate method until now. In implementing that method, configuration of base stations that serve as control points affects the localization accuracy. Thus, this paper discusses about optimal configuration of base stations. The variation in localization accuracy according to spatial relationship between an object and base stations Is mentioned through SEP also.

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Optimal Base Position and Joint Configuration of a Wheeled Manipulator

  • Kim, Sung-Bok;Kim, Hyoung-Gi
    • 제어로봇시스템학회:학술대회논문집
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    • 2004.08a
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    • pp.834-839
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    • 2004
  • In this paper, we investigate the optimal base position and joint configuration of a planar wheeled mobile manipulator in terms of manipulability measure. Taking into account the level of coordination between a manipulator and a platform, both local and global optimization problems are considered. First, based on the kinematic models of a mobile manipulator, the manipulability measures are expressed along with the analysis of the configurational dependency. Second, the geometric symmetry of a mobile manipulator in view of manipulability measure is analyzed, and for some base positions, the best and worst joint configurations are determined, Third, with reverence to the maximum, minimum, and average manipulability measures, the optimal base positions are determined, and the percent improvements due to the base relocation are discussed considering the relative scales among the platform size, the wheel radius, and the link length.

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MNCs R&D Subsidiary Strategy : Focusing on Technology Firm Patent Performance (다국적기업의 R&D 자회사 전략 : 기술기업 연구개발 특허성과를 중심으로)

  • Kim, Ji Yeon
    • Journal of Information Technology Applications and Management
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    • v.24 no.4
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    • pp.13-24
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    • 2017
  • This study aims to analyze which subsidiary configuration strategy is more effective under uncertainty especially technology base multinational corporations (henceforth MNCs). In previous studies real option theory scholars argue that high breadth subsidiary configuration is most effective strategy because that provides flexibility to MNCs global network. In this study I want unveil more various types of uncertainty such as technology and learning uncertainty which are more important for technology base firm and further more examine the effect of MNCs subsidiary configuration on firm R&D performance each uncertainty case. Empirical study is performed by negative binominal model based on Japanese 108 multinational corporations. The result shows that under technology uncertainty, high breadth subsidiary configuration is better for firm R&D performance but under learning uncertainty high depth subsidiary configuration is better. Thus, the effects of MNCs subsidiary configuration on firm value can differ by types of uncertainty.

A Study on the Application of Spatial Configuration to Escher's Oppositive Tessellation (에셔의 대립적 테셀레이션 작품의 공간구성 적용에 관한 연구)

  • You, Jung-Hwan;Lee, Ho-Joung
    • Korean Institute of Interior Design Journal
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    • v.17 no.5
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    • pp.40-50
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    • 2008
  • This article examined the applicability of spatial configuration to Escher's works through configurative logics and rules and studied the contrasting relations among the unit elements in Escher's works and their characteristics and the creative process of the characteristics. As the results of the study on the bases to maintain and create the partial elements revealed as the characteristics, it was shown that Escher's sequential transformative works demonstrated diverse expressive characteristics as a creative process of Inter-complementary contrasting relations based on the independence of the unit elements. It was also shown that the creative process of the unit elements was actualized through the maintenance base of the fixed and absolute characteristic as the logic for the creation and the creation base of the dynamic and relative characteristic. Therefore, it was interpreted that by applying the logics for creation to Escher's unit elements through the spatial interpretation of the maintenance base and the creation base as well as by configuring the units created in such a way according to the characteristics of Escher's works, spatial possibility canbe derived out from Escher's contrasting tessellation works. The process of spatial configuration is the process to make a balance between various conditions, artists own understanding of the space and his/her intention of the space. From this viewpoint, the logics for maintenance base and for creation base seem to have the potentiality as a spatial configuration to consistently meet the given conditions as well as to derive out novelty through the transformation to maintain the fixed and absolute condition(base) and the characteristics of the independent(additional) transformation arising together with the implicit relations among the transformative units.

Active tendon control of suspension bridges: Study on the active cables configuration

  • Tian, Zhui;Mokrani, Bilal;Alaluf, David;Jiang, Jun;Preumont, Andre
    • Smart Structures and Systems
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    • v.19 no.5
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    • pp.463-472
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    • 2017
  • In a previous study, the potential of damping suspension bridges with active stay cables has been evaluated on a numerical model of a suspension bridge, and demonstrated experimentally on a laboratory mockup. In this paper, we extend our study to explore two different configurations of the active stay-cables: one classical configuration, corresponding to attaching the active stay-cables between the top of the pylons and the deck (configuration I) and, another configuration, consisting of attaching the stay-cables between the base of the pylons and the catenary (configuration II). The analysis confirmed that both configurations are effective with a slight superiority of the second configuration. The study is conducted numerically and experimentally on a suspension bridge mock-up, by considering two types of active stay-cables. The experimental results confirmed the numerical predictions, and demonstrated the effectiveness of the second configuration.

Effect of semi-rigid connections in improvement of seismic performance of steel moment-resisting frames

  • Feizi, M. Gholipour;Mojtahedi, A.;Nourani, V.
    • Steel and Composite Structures
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    • v.19 no.2
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    • pp.467-484
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    • 2015
  • Seismic performances of dual steel moment-resisting frames with mixed use of rigid and semi-rigid connections were investigated to control of the base shear, story drifts and the ductility demand of the elements. To this end, nonlinear seismic responses of three groups of frames with three, eight and fifteen story were evaluated. These frames with rigid, semi-rigid and combined configuration of rigid and semi-rigid connections were analyzed under five earthquake records and their responses were compared in ultimate limit state of rigid frame. This study showed that in all frames, it could be found a state of semi-rigidity and connections configuration which behaved better than rigid frame, with consideration of the base shear and story drifts criterion. Finally, some criteria were suggested to locate the best place of the semi-rigid connections for improvement of the seismic performance of steel moment-resisting frames.

Navier-Stokes Computations and Experiment of The Supersonic Flows Over a Cylindrical Afterbody with Base Bleed

  • 김희동;권오식
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2000.04a
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    • pp.14-14
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    • 2000
  • One of the most important aerodynamic performance characteristics for projectiles is the total drag which can be typically divided into three components, pressure drag (excluding the base), viscous skin friction drag, and base drag. In a range of supersonic flight speeds the base drag is a major contributor to the total drag and can be as much as 50%∼70% of the total drag, depending on the afterbody configuration of projectiles. It is of especial importance to minimize this part of. the drag.

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A Study on the Task-Oriented Optimal Configuration of an ROV Mounted Manipulator Based on the Manipulability Measure (조작지수에 근거한 수중로봇팔의 작업지향적 최적자세에 관한 연구)

  • KIM Insik;JEON Bong-Hwan;LEE Pan Mook;LEE Jihong
    • Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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    • 2004.05a
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    • pp.48-53
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    • 2004
  • In this paper, the task-oriented optimal configuration in the sense of Velocity and Force manipulability measure of manipulator mounted on ROV is considered. Manipulability is a quantitative measure of manipulator's capability obtained under the limits of joint velocities or torques. The base arrangements and optimal joint configuration of manipulator, that maximize the manipulability measure under the constraints of given task, are investigated. With the two types of base arrangements of manipulator, workspace analysis is carried out to investigate merits and demerits of each arrangement on the view of manipulability measure. To find optimal joint configuration for a given task with each arrangement, the SQP(Sequential Quadratic Programming) optimization are performed. Weighted linear combination of velocity and force manipulability measure is object function for SQP optimization. The kinematic parameters of Dual Orion manipulator which will be mounted on KORDI ROV are used for simulation.

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Technical Trends of Medical AI Hubs (의료 AI 중추 기술 동향)

  • Choi, J.H.;Park, S.J.
    • Electronics and Telecommunications Trends
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    • v.36 no.1
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    • pp.81-88
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    • 2021
  • Post COVID-19, the medical legacy system will be transformed for utilizing medical resources efficiently, minimizing medical service imbalance, activating remote medical care, and strengthening private-public medical cooperation. This can be realized by achieving an entire medical paradigm shift and not simply via the application of advanced technologies such as AI. We propose a medical system configuration named "Medical AI Hub" that can realize the shift of the existing paradigm. The development stage of this configuration is categorized into "AI Cooperation Hospital," "AI Base Hospital," and "AI Hub Hospital." In the "AI Hub Hospital" stage, the medical intelligence in charge of individual patients cooperates and communicates autonomously with various medical intelligences, thereby achieving synchronous evolution. Thus, this medical intelligence supports doctors in optimally treating patients. The core technologies required during configuration development and their current R&D trends are described in this paper. The realization of the central configuration of medical AI through the development of these core technologies will induce a paradigm shift in the new medical system by innovating all medical fields with influences at the individual, society, industry, and public levels and by making the existing medical system more efficient and intelligent.