• Proceedings of the Korea Concrete Institute Conference
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• 2006.05a
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• pp.506-509
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• 2006

Extended Kalman Filter iterate the prediction and the filtering based on Initial state for the next time step. EKF method for the estimation of nonlinear parameters of a structural dynamic system is necessary that initial of state vector and error covariance matrix. Because those are unknown exactly, generally selected random values. That occasion observability problem appear because of unknown initial values. In this study, for the estimation of the nonlinear parameters, a simple one degree of Freedom example is carried out by Extended Kalman Filter. And initial value assumption for Parameter Estimation of Dynamic System are developed. The result of analysis is compared with calculated standard values.

• Journal of the Korean Ceramic Society
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• v.29 no.9
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• pp.711-718
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• 1992

Pb(Fe1/2Nb1/2)O3 was prepared by the molten salt synthesis method using an equimolar mixture of NaCl-KCl. Initial particle size could be controlled by varying the weight ratio of the NaCl-KCl to raw materials from 0.1 to 1.0, and the initial particle size effects on the sintering and dielectric properties of Pb(Fe1/2Nb1/2)O3 were investigated at the sintering temperature range from 90$0^{\circ}C$ to 105$0^{\circ}C$. As the weight ratio of salt increased, the average particle size decreased and the particle size distributions tended to narrow. As the initial particle size decreased, the linear shrinkage and density increased due to the promotion of densification. Dielectric constant increased with decreasing the initial particle size resulting from the increase of density and grain size.

• Journal of the Korean Home Economics Association
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• v.49 no.6
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• pp.13-22
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• 2011

This study investigated the influence of product attribute on initial trust and purchase intention of sensor-based smart clothing. Questionnaires were administered to 256 university students in Daegu, Korea. The results were as follows: First, there were 5 factor solutions in product attribute of smart clothing; comfortableness, health usefulness, management easiness, safety, and aesthetic appearance. Second, there were significant effects on initial trust in heath usefulness, management easiness and safety. Third, there were significant effects on purchase intention in health usefulness, management easiness and aesthetic appearance. Fourth, there was a significant effect on purchase intention in initial trust.

• Journal of information and communication convergence engineering
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• v.8 no.5
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• pp.519-523
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• 2010

In Gen-2 RFID system, the initial value of $Q_{fp}$, which is the slot-count parameter of Q-algorithm, is not defined in the standard. In this case, if the number of tags within the reader's identification range is small and we let the initial $Q_{fp}$ be large, the number of empty slot will be large. On the other hand, if we let the initial $Q_{fp}$ be small in spite of many tags, almost all the slots will be collided. As a result, the performance will be declined because the frame size does not converge to the optimal point quickly during the query round. In this paper, we propose a scheme to allocate the optimal initial $Q_{fp}$ through the tag number estimation before the query round begins. Through computer simulations, it is demonstrated that the proposed scheme achieves more stable performance than Gen-2 Q-algorithm.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.05b
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• pp.86-90
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• 2000

In this study, A equipment for measuring the initial permeability of soft-ferrite powder was developed by using a differential transformer coil, and was investigated demagnetizing factors. To measure the initial permeability of magnetic ceramic powder is cumbersome since there are not any measuring equipment and method. Magnetic powder is currently used for a magnetic fluid and microwave absorber materials, and the initial permeability of the magnetic powder is very important to be evaluated a powder for some applications.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.22 no.9
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• pp.889-895
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• 2012

A vertical launching system(VLS) is a system for holding and firing missiles on surface ships. When a missile is launched in VLS, relative motion between canister and missile and drag force induced by wind can cause initial unstability of a missile. Thus dynamic analysis of initial behavior of vertically launched missile should be performed to prevent collision with any structure of a ship. In this study, dynamic analyses of initial behavior of vertically launched missile are performed using Monte-Carlo simulation, which relys on random sampling and probabilistic distribution of variables. Each parameter related with dynamic behavior of a missile is modeled with probability variables and Recurdyn, a commercial software for multi body dynamic analysis, is used to perform Monte-Carlo simulation. As a result, initial behavior of a missile is evaluated with respect to various performance indexes in a probabilistic sense and sensitivity of the each parameters is calculated.

• The Bulletin of The Korean Astronomical Society
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• v.35 no.2
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• pp.35.1-35.1
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• 2010

Unlike the initial mass function, the initial size distribution of globular cluster (GC) systems is not well known. We calculate the evolution of the mass function (MF), radial distribution (RD), and size distribution (SD) of the Galactic GC system. By comparing the results from this calculation and the present-day MF, RD, and SD of the Galactic GC system, we infer the initial SD of the GC system. We find that a Gaussian distribution of the half-mass radius and a Gaussian distribution of the half-mass to Jacobi radius ratio are the best-fit initial SDs of the Galactic GC system.

• Journal of Ocean Engineering and Technology
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• v.18 no.3
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• pp.44-49
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• 2004

Initial hull form of 10 G/T and 40 knots class coastal patrol boat is newly developed. The resistance performances are experimentally and numerically investigated by model test and CFD technique. The effect of initial trim and a fin attached at hull side are studied together. Wave patterns are observed to make clear the relation between the performance and the wave characteristics. It can be found that the initial trim plays a role in increasing the resistance performance above a certain velocity, and the CFD technique can be used at the initial design stage of a high-speed planning boats.

• Journal of the Korean Institute of Telematics and Electronics B
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• v.30B no.8
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• pp.54-63
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• 1993

This paper proposes a method for improving the performances of the neural network for optimization by an optimal estimation of initial states. The optimal initial state that leads to the global minimum is estimated by using the stochastic approximation. And then the update rule of Hopfield model, which is the high speed deterministic algorithm using the steepest descent rule, is applied to speed up the optimization. The proposed method has been applied to the tavelling salesman problems and an optimal task partition problems to evaluate the performances. The simulation results show that the convergence speed of the proposed method is higher than conventinal Hopfield model. Abe's method and Boltzmann machine with random initial neuron output setting, and the convergence rate to the global minimum is guaranteed with probability of 1. The proposed method gives better result as the problem size increases where it is more difficult for the randomized initial setting to give a good convergence.

• Korean Management Science Review
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• v.13 no.3
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• pp.105-113
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• 1996

Constructing an initial basis is an important process in the simplex method. An initial basis greatly affects the number of iterations of iterations and the execution time in the simplex method. The purpose of this paper is to construct a good initial basis. First, to avoid linear dependency among the chosen columns, an enhanced Gaussian elimination method and a method using non-duplicated nonzero elements are developed. Second, for an order to choose variables, the sparsity of the column is used. Experimenal results show that the proposed method can reduce the number of iterations and the execution time compared with Bixby's method by 12%.