• 한국기계연구소 소보
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• s.10
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• pp.35-48
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• 1983

When the hydrodynamic coefficients of the ship maneuvering equation are estimated by captive model test, it is difficult to take account of the scale effect between model and full scale ship. This scale effect problem can be overcome by processing the sea trial data with system identification. Extended Kalman filter is used as a system identification technique for the modification of the simulation equation as well as the estimation of hydrodynamic coefficients. The phenomena of simultaneous drifting of linear coefficients occur. It is confirmed that two coefficients in each pair-($Y_v$', $Y_r$' -m' u'), ($N_v$', $N_r$' )-are simultaneously drifting and all 4 coefficients are simultaneously drifting together. Particularly simultaneous drifting of 2 coefficients in each pair is more significant. It is also shown that the simultaneous drifting of 4 coefficients can be reduced by choosing the input data which have the random v'/r' curve and 4 coefficients are estimated within 2-4% error, which may be noise level. So, it is recommended to operate the rudder randomly in sea trial or model test for the application of system identification technique.

• Wind and Structures
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• v.19 no.1
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• pp.35-58
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• 2014

A numerical simultaneous solution involving a linear elastic model was applied to study the fluid-structure interaction (FSI) of membrane structures under wind actions, i.e., formulating the fluid-structure system with a single equation system and solving it simultaneously. The linear elastic model was applied to managing the data transfer at the fluid and structure interface. The monolithic equation of the FSI system was formulated by means of variational forms of equations for the fluid, structure and linear elastic model, and was solved by the Newton-Raphson method. Computation procedures of the proposed simultaneous solution are presented. It was applied to computation of flow around an elastic cylinder and a typical FSI problem to verify the validity and accuracy of the method. Then fluid-structure interaction analyses of a saddle membrane structure under wind actions for three typical cases were performed with the method. Wind pressure, wind-induced responses, displacement power spectra, aerodynamic damping and added mass of the membrane structure were computed and analyzed.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.11
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• pp.6565-6575
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• 2014

Hamilton's Markov-switching model [5] was extended to the simultaneous equations model. A framework for an instrumental variable interpretation of full information maximum likelihood (FIML) by Hausman [4] can be used to deal with the problem of simultaneous equations based on the Hamilton filter [5]. A comparison of the proposed FIML Markov-switching model with the LIML Markov-switching models [1,2,3] revealed the LIML Markov-switching models to be a special case of the proposed FIML Markov-switching model, where all but the first equation were just identified. Moreover, the proposed Markov-switching model is a general form in simultaneous equations and covers a broad class of models that could not be handled previously. Excess sensitivity of marginal propensity to consume with big shocks, such as housing bubble bursts in 2008, can be determined by applying the proposed model to Campbell and Mankiw's consumption function [6], and allowing for the possibility of structural breaks in the sensitivity of consumption growth to income growth.

• Journal of Mechanical Science and Technology
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• v.14 no.1
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• pp.57-64
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• 2000

Recent advances in the field of control theory have enabled us to design active vibration control systems for various structures. In many studies, the controller used to suppress vibration has been synthesized for the given mathematical model of structure. In these cases, the designer has not been able to utilize the degree of freedom to adjust the structural parameters of the control object. To overcome this problem, so called 'Structure/Control Simultaneous Optimization Method' is used. In this context of view, this paper is concerned with the active vibration control of bridge towers, platforms and ocean vehicles etc. Simultaneous design method is used to achieve optimal system performance. Here, a general framework for the simultaneous design problem of output feedback case is introduced based on LMI (Linear Matrix Inequality). The simulation results show that the proposed design method achieves desirable control performance.

• Communications for Statistical Applications and Methods
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• v.21 no.1
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• pp.11-22
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• 2014

In this study, we propose a simultaneous test procedure based on the individual - values for each sub-null hypothesis with several well-known combining functions. We then compare the efficiency of our procedure with existing tests by obtaining empirical powers through a simulation study. Finally, we discuss some interesting features related to simultaneous test and point out a misconduct for the simulation study published in the previous work.

• Communications for Statistical Applications and Methods
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• v.16 no.1
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• pp.115-125
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• 2009

Simultaneous equation models, which are widely used in business and economic areas, generally consist of endogenous variables determined within models and exogenous variables externally determined and in the simultaneous equations model framework there are rank and order conditions for the model identification and the existence of unique solutions. By contrast, their estimating results have less efficiencies and furthermore do not exist, since the most estimating procedures are performed under the assumptions for rank and order conditions. We propose the new statistical test for sufficiency of the rank condition under the order condition, and show the asymptotic properties for the test. The Monte Carlo simulation studies are achieved in order to evaluate its power and to suggest the baseline for satisfying the rank conditions.

• Proceedings of the IEEK Conference
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• 1998.10a
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• pp.1141-1144
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• 1998

A new design methodology for the shortchannel CMOS IC-package is presented. It is developed by representing the package inductance with an effective lumpedinductance. The worst case maximum-simultaneous-switching noise (SSN) and gate propagation delay due to the package are modeled in terms of driver geometry, the maximum number of simultaneous switching drivers, and the effective inductance. The SSN variations according to load capacitances are investigated with this model. The package design techniques based on the proposed guidelines are verified by performing HSPICE simulations with the $0.35\mu\textrm{m}$ CMOS model parameters.

• Journal of the Korean Statistical Society
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• v.23 no.1
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• pp.53-62
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• 1994

When a comparison is made with respect to the unknown best treatment, Hsu (1984, 1985) proposed the so called multiple comparisons procedures with the best in the analysis of variance model. Applying Hsu's results to the analysis of covariance model, simultaneous confidence intervals for multiple comparisons with the best in a balanced one-way layout with a random covariate are developed and are applied to a real data example.

• Proceedings of the IEEK Conference
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• 1999.06a
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• pp.389-392
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• 1999

It is essential to estimate an effective inductance in a ground plane of muliti-layer IC package system in order to determine the simultaneous switching noise of the package. A new method to estimate the effective ground inductance in multi-layer IC package is presented. With the estimated ground plane inductance values, maximum switching noise variations according to the number of simultaneously switching drivers are investigated by developing a new SSN model. These results are verified by performing HSPICE simulation with the 0.35${\mu}{\textrm}{m}$ CMOS technology.

• Journal of Korean Institute of Industrial Engineers
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• v.22 no.4
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• pp.677-687
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• 1996

We study simultaneous decision making model for a monopolistic or competitive supplier to decide inventory and pricing policies under capacity constraint. Economic implications are obtained from the optimality conditions such as production lot sizes, pricing schedules and so on. Sensitivity analysis gives us the optimal relations among the critical economic quantities.