• Title/Summary/Keyword: stepping

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Identification of Multiple Outlying Cells in Multi-way Tables

  • Lee, Jong Cheol;Hong, Chong Sun
    • Communications for Statistical Applications and Methods
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    • v.7 no.3
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    • pp.687-698
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    • 2000
  • An identification method is proposed in order to detect more than one outlying cells in multi-way contingency tables. The iterative proportional fitting method is applied to get expected values of several suspected outlying cells. Since the proposed method uses minimal sufficient statistics under quasi log-linear models, expected counts of outlying cells could be estimated under any hierarchical log-linear models. This method is an extension of the backwards-stepping method of Simonoff(1988) and requires les iteration to identify outlying cells.

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An Automatic Time Stepping Algorithm Using a Prior Error Estimator in Structural Dynamics (구조동역학 문제에서 전단계 오차추정치를 이용한 자동시간간격 조정 알고리듬)

  • 조은형;정진태
    • Journal of KSNVE
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    • v.9 no.6
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    • pp.1240-1246
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    • 1999
  • A prior error estimator which is solving structural dynamic problems and which is based on the generalized-method, is developed. Since the proposed error estimator is computed with only previous information, the time step size can be adaptively selected without the feedback mechanism. This paper shows that the automatic time stepping algorithm using the error estimator performs an efficient time integration. To verify its efficiency, several examples are numerically investigated.

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Analysis of Dynamic Instability in a Variable-reluctance Stepping Motor Operated on Frequency-modulated Supply (주파수변조 구동에 의한 가변릴럭턴스 스텝핑모우터의 불안정 해석)

  • Kwon, Yong-Soo
    • Proceedings of the KIEE Conference
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    • 1994.07a
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    • pp.114-118
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    • 1994
  • A comprehensive analytical study of frequency-modulated supply of the dynamic instability in a variable-reluctance stepping motor, is described. It is shown that stability can be achieved by frequency modulation provided that the phase displacement between the modulating signal and the rotor velocity oscillation lies between certain limits. A simplified expression is derived. based on the assumption of high inertia. This model is used to obtain a qualitative understanding of how frequency modulation influences the dynamic stability of the variable-reluctance motor.

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Automate Door Using Control IC (제어 IC 및 이를 이용한 자동문(Auto Door) 제작)

  • 권경민;허창우
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2002.11a
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    • pp.686-692
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    • 2002
  • 본 논문은 Pyroelectric Sensor의 신호를 입력으로 받아 Stepping Motor 제어신호를 출력하는 Controller를 VHDL을 이용하여 ALTERA사의 EPM7128SLC84-7 CPLD칩으로 구현하여 자동문을 제작하였다. 동작은 센서부에서 사람을 감지하여 출력한 신호를 CPLD에서 받아들여 Stepping Motor구동부 회로의 제어신호로 사용하여 문을 동작시켰다.

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Preconditioned Multistage time stepping for the Multigrid Navier-Stokes Solver (다중 격자 Navier-Stokes 해석을 위한 예조건화된 다단계 시간 전진 기법)

  • Kim Yoonsik;Kwon Jang Hyuk;Choi Yun Ho;Lee Seungsoo
    • 한국전산유체공학회:학술대회논문집
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    • 2002.05a
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    • pp.59-64
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    • 2002
  • In this paper, the preconditioned multistage time stepping methods which are popular multigrid smoothers is implemented for the compressible Navier-Stokes calculation with full-coarsening multigrid method. The convergence characteristic of the point-Jacobi and Alternating direction line Jacobi(DDADI) preconditioners are studied. The performance of 2nd order upwind numerical fluxes such as 2nd order upwind TVD scheme and MUSCL-type linear reconstruction scheme are compared in the inviscid and viscous turbulent flow caculations.

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Analysis of Current Waveforms in Variable-reluctance Stepping Motors (가변릴럭턴스 스텝핑모터의 전류파형 해석)

  • Kwon, Yong-Soo
    • Proceedings of the KIEE Conference
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    • 1995.07a
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    • pp.116-118
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    • 1995
  • A comprehensive analytical study of total-intake current waveforms is described. In particular, the characteristics of the modulation envelope of the waveforms are the subject of detailed investigation. It is shown that the lower modulation envelope of the total intake current is capable of providing a signal suitable for use in stabilising a variable-reluctance stepping motor.

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Effective points for acupuncture are different from induction methods in rat models of arthiritis (관절염 유발 방법에 따른 경혈의 진통효과 차이)

  • Koo, Sung-Tae;Kim, Yu-Sung;Lee, Ji-Eun;Hwang, Hye-Suk;Han, Kyung-Ju;Choi, Sun-Mi
    • Korean Journal of Oriental Medicine
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    • v.12 no.3 s.18
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    • pp.49-58
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    • 2006
  • Although the usage of acupuncture for pain has increased in recent years, the mechanisms of acupuncture analgesia (AA) remain unclear. The lack of suitable experimental animal models for persistent pain, which show clear AA, has been the major stumbling block in the investigation of the physiological mechanisms of AA. In the present study, we test AA in two knee arthritis models induced by injection of CFA or carrageenan as persistent pain models. After induction of arthritis, the rat subsequently showed a reduced stepping force of the affected limb for the next several days. Electroacupuncture (EA) was applied to an acupuncture point each on the contralateral forelimb for 30 minutes under gaseous anesthesia. After the termination of EA, behavioral tests measuring stepping force were periodically conducted during the next several hours. EA produced a significant improvement of stepping force of the foot lasting for at least 2 hours when applied to LR2 in CFA model, and applied to ST36 in carrageenan model, but both points did not produce any significant effects in each other model. Further experiments showed that intraperitoneal pretreatment of naltrexone, a non-selective opioid antagonist, did not reduced the EA-induced improvement of stepping force in both of two models. These data suggest that EA produce analgesic effect in knee arthritic pain and the analgesic effect is specific to the acupuncture point depending on painful conditions.

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Characteristics of Time Stepping and Harmonic Finite Element Models for Coastal Hydrodynamic Simulation (연안 수훈력학 모난를 위한 시간진행 및 조화 유한요소모형 특성)

  • 서승원
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.5 no.4
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    • pp.406-413
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    • 1993
  • Among 2-dimensional coastal hydrodynamic finite element models time stepping ADCIRC and STEPM. and harmonic FUNDY and TEA models were compared in order to find out their characteristics and analyze ernr. General feasibility and capability of models were studied by comparing model results with an analytical solution on some reference points and L$_2$norm error in quarter annular domain where analytical solution can be obtained. According to these tests harmonic models FUNDY and TEA were nearly coinciding with analytical solutions and gave better results than time stepping models. STEPM was at least 5 times better than ADCIRC in L$_2$norm error test and it was 7 times worse than harmonic models. It was expected and concluded that these errors might come from phase lag due to cold start condition and nonlinear effect in basic equations of time stepping models.

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