• Title, Summary, Keyword: Boundary shifting

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Vagueness and the Context-Fixing Argument (모호성과 맥락고정논변)

  • Lee, Jun-Hyo
    • Korean Journal of Logic
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    • v.14 no.1
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    • pp.23-54
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    • 2011
  • In this paper, I introduce what Boundary-Shifting theories of vagueness (or Contextualism about vagueness) are and what the Context-Fixing Argument is, which is the most powerful and plausible objection to Boundary-Shifting theories. The basic idea of the Context-Fixing Argument is that vagueness still remains even if we hold the context fixed. Many objections based on this simple idea can be found in the literature on Boundary-Shifting theories. It seems that, without a convincing response to the Context-Fixing Argument, Boundary-Shifters must be in trouble. But, oddly, defenders of Boundary Shifters have said very little about this matter. In this situation, ${\AA}$kerman and Greenough try to defend Boundary-Shifting theories of vagueness by suggesting several answers. In this paper, I critically examine their suggestions and develop a new answer to the Context-Fixing Argument.

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Analysis of Topological Effects of Phase-Shifting Mask by Boundary Element Method (경계요소법을 이용한 위상변이 마스크의 단차 효과 분석)

  • Lee, Dong-Hoon;Kim, Hyun-Jun;Lee, Seung-Gol;Lee, Jong-Ung
    • Journal of the Korean Institute of Telematics and Electronics D
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    • v.36D no.11
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    • pp.33-44
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    • 1999
  • The boundary element method was newly implemented into an optical lithography simulator so that it could evaluate rigorously the topological effects of 2dimensional phase-shifting masks. Both transparent and periodic boundary conditions were applied for the method, and the continuity conditions were used for treating interface nodes. The accuracy of the module developed for simulating aerial images was verified by comparison with analytic solutions and published results. In addition, it was found that our simulator would be more efficient than the conventional method based on the rigorous coupled wave analysis in views of the convergence and the calculation speed. Finally, the optimal design of two phase-shifting masks was performed.

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the Combination of Wavelet with Boundary Element Method for the Efficient Solution of Maxwell's Equations (Maxwell 방정식의 효율적인 풀이를 위한 경계요소법과 웨이브렛의 결합)

  • Kim, Hyun-Jun;Lee, Seung-Gol;O, Beom-Hoan;Lee, El-Hang
    • Journal of the Institute of Electronics Engineers of Korea CI
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    • v.39 no.6
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    • pp.24-35
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    • 2002
  • The wavelet transform is combined with the boundary element method (BEM), to solve efficiently the Maxwell's equation and the proposed method is applied to the electromagnetic problem for the analysis of topological effects of phase-shifting masks. The accuracy of the module developed was verified by comparison with both analytic solutions and published results. In addition, it was found that the boundary element method in combination with the wavelet matrix transform would be more efficient than the conventional methods based on the BEM in views of the calculation speed and the usage of computer memory.

Shape Optimization of High Voltage Gas Circuit Breaker Using Kriging-Based Model And Genetic Algorithm (크리깅 메타모델과 유전자 알고리즘을 이용한 초고압 가스차단기의 형상 최적 설계)

  • Kwak, Chang-Seob;Kim, Hong-Kyu;Cha, Jeong-Won
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.62 no.2
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    • pp.177-183
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    • 2013
  • We describe a new method for selecting design variables for shape optimization of high-voltage gas circuit breaker using a Kriging meta-model and a genetic algorithm. Firstly we sample balance design variables using the Latin Hypercube Sampling. Secondly, we build meta-model using the Kriging. Thirdly, we search the optimal design variables using a genetic algorithm. To obtain the more exact design variable, we adopt the boundary shifting method. With the proposed optimization frame, we can get the improved interruption design and reduce the design time by 80%. We applied the proposed method to the optimization of multivariate optimization problems as well as shape optimization of a high - voltage gas circuit breaker.

Stress Analysis at the Contact Boundary between the Work Roll and the Back-up Roll for a SmartCrown Roll Profile Shape (SmartCrown Roll Profile 형상에 따른 Work Roll과 Back-up Roll 접촉경계면의 응력해석)

  • Song, S.H.;Kim, S.R.;Kim, K.W.
    • Transactions of Materials Processing
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    • v.24 no.3
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    • pp.212-217
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    • 2015
  • SmartCrown is a system to control the plate crown by shifting the sine-shaped work rolls in the axial direction. The control range of the plate crown depends on a depth of sine-shaped roll profile because the roll radius varies continuously along the axial direction. When the roll profile is changed to improve the control range, the contact stress between the work roll and the back-up roll also changes. In the current study, the contact stress for various profiles and rolling conditions were analyzed using the finite element method and compared with results from Hertzian contact theory. A submodel method is used to increase the accuracy of the finite element analysis. The analysis results showed that the maximum increase in the contact stress was only 53MPa, so it is anticipated that no back-up roll spalling will occur.

Drift Control for Multistory Moment Frames under Lateral Loading

  • Grigorian, Carl E.;Grigorian, Mark
    • International Journal of High-Rise Buildings
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    • v.2 no.4
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    • pp.355-365
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    • 2013
  • The paper reports results of recent studies on the effects of column support conditions on the lateral displacements of moment frames at incipient collapse. The article presents a number of exercises in the plastic theory of structures that lead to useful design formulae. It has been shown that Drift Shifting (DS) is caused due to differences in the stiffnesses of adjoining columns, and that changes in drift ratios are more pronounced at first level column joints in both fixed as well as pinned base frames. In well proportioned moment frames, DS in the upper levels could be minimized, even reduced to zero. It has been demonstrated that DS can be eliminated in properly designed fixed and grade beam supported (GBS) moment frames. Several examples, including symbolic P-delta effects, have been provided to demonstrate the validity and the applications of the proposed ideas to the design and drift control of moment frames. The proposed methodology is exact within the bounds of the theoretical assumptions and is well suited for preliminary design and teaching purposes.

Analysis of the Phase Current Measurement Boundary of Three Shunt Sensing PWM Inverters and an Expansion Method

  • Cho, Byung-Geuk;Ha, Jung-Ik;Sul, Seung-Ki
    • Journal of Power Electronics
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    • v.13 no.2
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    • pp.232-242
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    • 2013
  • To obtain phase currents information in AC drives, shunt sensing technology is known to show great performance in cost-effectiveness and therefore it is widely used in low cost applications. However, shunt sensing methods are unable to acquire phase currents in certain operation conditions. This paper deals with the derivation of the boundary conditions for phase current reconstruction in three-shunt sensing inverters and proposes a voltage injection method to expand the measurable areas. As the boundary conditions are deeply dependent on the switching patterns, they are typically analyzed on the voltage vector plane for space vector pulse width modulation (SVPWM) and discontinuous pulse width modulation (DPWM). In the proposed method, the voltage injection and its compensation are conducted within one sampling period. This guarantees fast current reconstruction and the injected voltage is decided so as to minimize the current ripple. In addition to the voltage injection method, a sampling point shifting method is also introduced to improve the boundary conditions. Simulation and experimental results are presented to verify the boundary condition derivation and the effectiveness of the proposed voltage injection method.

Computation of a Low Strain Rate Counterflow Flame in Normal and Zero Gravity (정상중력 및 무중력에서의 저변형율 대향류화염의 전산)

  • Woe-Chul Park
    • Journal of the Korean Society of Safety
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    • v.17 no.3
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    • pp.107-111
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    • 2002
  • A near extinction nonpremixed counterflow flame of 19% methane diluted by 81% nitrogen by volume and undiluted air at a low global strain rate, 20 s-1, was computed. Investigations were focused on effects of the duct thickness and velocity boundary conditions on the flame structure in normal and zero gravity conditions. The results showed that, under normal gravity conditions, the effects of the duct thickness and velocity boundary conditions were significant by shifting the flame position, but negligible in zero gravity. The differences in flame structure were caused by buoyancy, and hence should be considered in the measurements in normal gravity.

Dynamic Manipulability Analysis of Underwater Robotic Arms with Joint Velocities (관절속도를 가지는 수중로봇팔의 동적 조작도 해석)

  • JEON BONG-HWAN;LEE JIHONG;LEE PAN-MOOK
    • Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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    • pp.204-209
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    • 2004
  • This paper describes dynamic manipulability analysis of robotic arms moving in viscous fluid. The Manipulability is a functionality of manipulator system in a given configuration and under the limits of joint ability with respect to the tasks required to bt performed. To investigate the manipulability of underwater robotic arms, a modeling and analysis method are presented. The dynamic equation of motion of underwater manipulator is derived from the Lagrange - Euler equation considering with the hydraulic forces caused by added mass, buoyancy and hydraulic drag. The hydraulic drag term in the equation: is established as analytical form using Denavit - Hartenberg (D-H) link coordination of manipulator. Two analytical approaches based on Manipulability Ellipsoid are presented to visualize the manipulability of robotic arm moving in viscous fluid. The one is scaled ellipsoid which transforms the boundary of joint torque to acceleration boundary of end-effector by normalizing the torque in joint space while the other is shifted ellipsoid which depicts total acceleration boundary of end-effector by shifting the ellipsoid in work space. An analysis example of 2-link manipulator with proposed analysis scheme is presented to validate the method.

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Dynamic Modeling and Manipulability Analysis of Underwater Robotic Arms (수중로봇팔의 동역학 모델링과 동적 조작도 해석)

  • Jnn Bong-Huan;Lee Jihong;Lee Pan-Mook
    • Journal of Institute of Control, Robotics and Systems
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    • v.11 no.8
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    • pp.688-695
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    • 2005
  • This paper describes dynamic manipulability analysis of robotic arms moving in viscous fluid. The manipulability is a functionality of manipulator system in a given configuration under the limits of joint ability with respect to the task required to be performed. To investigate the manipulability of underwater robotic arms, a modeling and analysis method is presented. The dynamic equation of motion of underwater manipulator is derived based on the Lagrange-Euler equation considering with the hydrodynamic forces caused by added mass, buoyancy and hydraulic drag. The hydrodynamic drag term in the equation is established as analytical form using Denavit-Hartenberg (D-H) link coordination of manipulator. Two analytical approaches based oil manipulability ellipsoid are presented to visualize the manipulability of robotic arm moving in viscous fluid. The one is scaled ellipsoid which transforms the boundary of joint torque to acceleration boundary of end-effector by normalizing the torques in joint space, while the other is shifted ellipsoid which depicts total acceleration boundary of end-effector by shifting the ellipsoid as much as gravity and velocity dependent forces in work space. An analysis example of 2-link manipulator with proposed analysis scheme is presented to validate the method.