• Title/Summary/Keyword: Right-handed

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NUMERICAL SIMULATION OF DAM-BROKEN PROBLEMS USING A PARTICLE METHOD (입자법을 이용한 댐 붕괴의 수치 시뮬레이션)

  • Lee, B.H.;Jung, S.J.;Kim, Y.H.;Park, J.C.
    • Journal of computational fluids engineering
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    • v.13 no.1
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    • pp.28-34
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    • 2008
  • A particle method recognized as one of the gridless methods has been developed to investigate the nonlinear free-surface motions interacting to the structures. The method is more feasible and effective than convectional grid methods for solving the non-linear free-surface motion with complicated boundary shapes. The right-handed side of the governing equations for incompressible fluid, which includes gradient, viscous and external force terms, can be replaced by the particle interaction models. In the present study, the developed method is applied to the dam-broken problem on dried- and wet-floor and its adequacy will be discussed by the comparison with the experimental results.

D-CRLH Based Band Rejection Filter using a Concavo-Convex Coupled CPW Transmission Line

  • Seo, Soo-Duk;Cho, Hak-Rae;Yang, Doo-Yeong
    • Journal of Electrical Engineering and Technology
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    • v.11 no.2
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    • pp.463-469
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    • 2016
  • In this paper, the use of a dual composite right/left-handed coplanar waveguide (CPW) transmission line is proposed for the design of a band rejection filter. The notch property of the filter is achieved by combining the convex signal line with the shorted concave meander line, and the equivalent circuit model is extracted from the geometry of the unit cell for organizing the band rejection property. Then the equivalent parameters of the unit cell are analyzed to identify those behaviors. And the dispersion characteristics and energy distributions are simulated. In the end, the band rejection filter is manufactured by cascading two proposed unit cells. We show that the measurement result for the resonant frequency demonstrates good agreement with the simulation result and the band rejection filter provides a rejection performance of 17.5 dB at the stopband frequency ranging from 869 MHz to 894 MHz.

DYNAMICAL CHARACTERISTICS OF SUNSPOT CHROMOSPHERES I. ANALYSIS OF CIRCULAR POLARIZATION MEASURED FROM A SUNSPOT

  • KIL HYO SUB;YUN HONG SIK
    • Journal of The Korean Astronomical Society
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    • v.26 no.2
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    • pp.103-114
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    • 1993
  • We have analyzed a set of high resolution photographic line profiles of a Zeeman sensitive Fe I $\lambda$ 6302.5 line taken with the Universal Birefringent Filter over a single round sunspot (SPO 5007) at the Sacramento Peak Solar Observatory. The observed spectra recorded on films are traced by PDS and the traced densities are converted to relative intensity by means of IRAF. The Stokes I and V profiles are then constructed by adding together and subtracting from each other the left and right handed circular polarizations, respectively. The reduced I and V profiles are analyzed by means of the coarse analysis(Auer et al.(1977), Skumanich and Lites(1987)) with the use of inversion technique. It is found that the umbral field strength is about 3000 gauss and the field distribution follows closely the emperical model proposed by Wittmann(1974).

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Generalized Stability Condition for Descriptor Systems (특이시스템의 일반적 안정화)

  • Oh, Do-Chang;Lee, Dong-Gi;Kim, Jong-Hae
    • Journal of Institute of Control, Robotics and Systems
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    • v.18 no.6
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    • pp.513-518
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    • 2012
  • In this paper, we propose a generalized index independent stability condition for a descriptor systemwithout any transformations of system matrices. First, the generalized Lyapunov equation with a specific right-handed matrix form is considered. Furthermore, the existence theorem and the necessary and sufficient conditions for asymptotically stable descriptor systems are presented. Finally, some suitable examples are used to show the validity of the proposed method.

Isolation Circuits Based on Metamaterial Transmission Lines for Multiplexers(Invited Paper)

  • Lee, Hanseung;Itoh, Tatsuo
    • Journal of electromagnetic engineering and science
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    • v.13 no.3
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    • pp.141-150
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    • 2013
  • Multiplexers based on isolation circuits made of metamaterial lines are proposed and studied. The new approach provides unique advantageous features beneficial to system designer. For instance, there is no need to modify the filters used in multiplexers. Also, the design process is straightforward. In this paper, two types of multiplexers based on metamaterial isolation circuits are presented, and their operation concepts are explained. Also, theories and design process of isolation circuits are presented to help readers design and fabricate proposed multiplexers. For verifying the concepts, two types of triplexers and two types of quadruplexers are designed and fabricated. All filters used in the multiplexers are commercial surface acoustic wave filters. The measured results are well matched with the simulation results.

NUMERICAL SIMULATION OF DAM-BROKEN PROBLEMS USING A PARTICLE METHOD (입자법을 이용한 댐 붕괴의 수치 시뮬레이션)

  • Park, J.C.;Lee, B.H.;Jung, S.J.
    • 한국전산유체공학회:학술대회논문집
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    • 2007.10a
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    • pp.258-263
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    • 2007
  • A particle method recognized as one of the gridless methods has been developed to investigate the nonlinear free-surface motions interacting to the structures. The method is more feasible and effective than convectional grid methods for solving the non-linear free-surface motion with complicated boundary shapes. The right-handed side of the governing equations for incompressible fluid, which includes gradient, viscous and external force terms, can be replaced by the particle interaction models. In the present study, the developed method is applied to the dam-broken problem on dried- and wet-floor and its adequacy will be discussed by the comparison with the experimental results.

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The Effect of Cross Education using Serial Reaction Time (연속반응시간과제를 이용한 교차훈련의 효과)

  • Choi, Jin-Ho;Park, So-Hyun
    • The Journal of Korean Physical Therapy
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    • v.20 no.4
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    • pp.15-20
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    • 2008
  • Purpose: We investigated the effects of physical practice, mental practice, and cross education using serial reaction time (SRT). We recruited 21 right-handed healthy males and females who gave consent and had no clinical history for their upper limbs. Methods: The subjects were divided into three groups; actual practice (n=7), mental practice (n=7), and controls (n=7), who performed actual training, mental training, or no intervention respectively for three weeks. Super lab 4.0 displayed four symbols on the monitor and subjects pushed on the matching button, with reaction time assessed pre- and post-intervention. Results: Reaction time was significantly lower after actual or mental practice (p<0.05). Actual practice also decreased left hand reaction time. Conclusion: Actual practice and mental practice can improve motor learning, but mental practice is not sufficient for cross education.

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CPW-Fed Arbitrary Frequency-Switchable Antenna Using CRLH Transmission Line

  • Lim, Inseop;Lim, Sungjoon
    • ETRI Journal
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    • v.36 no.1
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    • pp.151-154
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    • 2014
  • A novel frequency-switchable antenna that uses PIN diodes and a composite right- and left-handed transmission line (CRLH TL) is proposed. The CRLH TL provides multi-order resonance, including a zeroth-order resonance (ZOR), and its shunt stub determines the ZOR frequency. Thus, the resonant frequency is arbitrarily chosen by lumped chip inductors on the shunt stub. Two prototypes are designed using different chip inductors while maintaining the antenna geometries. Antenna #1 can switch the resonant frequency from 1.8 GHz to 2.3 GHz. Antenna #2 can switch its resonance from 0.9 GHz to 2.3 GHz.

The Comparison of the Cerebral Motor Area Activation between Diagonal and Straight Exercises of the Lower Extremity -A Case Study- (하지의 대각선 운동과 직선 운동 시 대뇌 운동영역 활성도 비교 -사례연구-)

  • Lee, Seuong-Yun;Rhee, Min-Hyung
    • PNF and Movement
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    • v.14 no.3
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    • pp.231-236
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    • 2016
  • Purpose: The purpose of this study was to compare cerebral motor area activation between the diagonal and straight movements of the lower extremity. Methods: The subjects of this study consisted of two right-handed adults. Functional magnetic resonance imaging was conducted to measure brain activation following the diagonal and straight movements of the lower extremity. The primary motor area, premotor area, and supplementary motor area, which are closely related to exercise, were set as the regions of interest. Results: The brain activation by diagonal movement was an average of $1036{\pm}75$ voxel, and brain activation by straight exercise was an average of $773{\pm}55$ voxel. Conclusion: Based on these results, we conclude that the activation of the cerebral motor area is more effective for diagonal movements than for straight movements.

Live Electrooptic Imaging Camera for Real-Time Visual Accesses to Electric Waves in GHz Range

  • Tsuchiya, Masahiro;Shiozawa, Takahiro
    • Journal of electromagnetic engineering and science
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    • v.11 no.4
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    • pp.290-297
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    • 2011
  • Recent progresses in the live electrooptic imaging (LEI) technique are reviewed with emphasis on its functionality of real-time visual accesses to traveling electric waves in the GHz range. Together with the principles, configurations, and procedures for the visual observation experiments by an LEI camera system, the following results are described as examples indicating the wide application ranges of the technique; Ku-band waves on arrayed planar antennas, waves on a Gb/s-class digital circuit, W-band waves traveling both in slab-waveguide modes and aerially, backward-traveling wave along composite right/left-handed transmission line, and, waves in monolithic microwave integrated circuit module case.