• IEMEK Journal of Embedded Systems and Applications
• /
• v.8 no.4
• /
• pp.219-225
• /
• 2013

This paper presents a method using Maximum-Likelihood Linear Regression (MLLR) adaptation to improve recognition performance of Limabeam algorithm for speech recognition using microphone array. From our investigation on Limabeam algorithm, we can see that the performance of filtering optimization depends strongly on the supporting optimal state sequence and this sequence is created by using Viterbi algorithm trained with HMM model. So we propose an approach using MLLR adaptation for the recognition of speech uttered in a new environment to obtain better optimal state sequence that support for the filtering parameters' optimal step. Experimental results show that the system embedded with MLLR adaptation presents the word correct recognition rate 2% higher than that of original calibrate Limabeam and also present 7% higher than that of Delay and Sum algorithm. The best recognition accuracy of 89.4% is obtained when we use 4 microphones with 5 utterances for adaptation.

• Journal of Industrial Technology
• /
• v.21 no.A
• /
• pp.231-240
• /
• 2001

U-turn and P-turn as well as left-turn restriction exist in real traffic network. the optimal route should be selected for considering these using shortest path algorithms. But, the traditional algorithms have some limitations to use for considering there. The objective of this paper is to modify Dijkstra algorithm in order to find the optimal path in real traffic network. The continuous three nodes are used to check turn-restrictions and exclude these from and optimal path. A virtual connection is used to consider U-turn and P-turn.

• 제어로봇시스템학회:학술대회논문집
• /
• 1995.10a
• /
• pp.10-13
• /
• 1995

This paper considers the linear-quadratic optimal regulator problem for nonstandard singularly perturbed systems making use of the recursive technique. We first derive a generalized Riccati differential equation by the Hamilton-Jacobi equation. In order to obtain the feedback gain, we must solve the generalized algebraic Riccati equation. Using the recursive technique, we show that the solution of the generalized algebraic Riccati equation converges with the rate of convergence of O(.epsilon.). The existence of a bounded solution of error term can be proved by the implicit function theorem. It is enough to show that the corresponding Jacobian matrix is nonsingular at .epsilon. = 0. As a result, the solution of optimal regulator problem for nonstandard singularly perturbed systems can be obtained with an accuracy of O(.epsilon.$^{k}$ ). The proposed technique represents a significant improvement since the existing method for the standard singularly perturbed systems can not be applied to the nonstandard singularly perturbed systems.

• 제어로봇시스템학회:학술대회논문집
• /
• 1990.10b
• /
• pp.1060-1065
• /
• 1990

In general it is difficult to determine a Liapunov function for a given asymptotically stable, nonlinear differential equations system. But, in the system with control inputs, it is feasible to make a given positive function, except for a small area, globally satisfy the conditions of the Liapunov function for the system. We call such a positive function a Liapunov-like function, and propose a method of nonlinear optimal regulator using this Liapunov-like function. We also use the periodic Liapuitov-like friction that suits the system whose equilibrium points exist periodically. The relationship between the Liapunov function and cost function which this nonlinear regulator minimizes is considered using inverse optimal method.

• Journal of the Korean Society for Railway
• /
• v.8 no.5
• /
• pp.411-418
• /
• 2005

This paper expounds the development of a user-friendly expert system for the optimal stacking sequence design of composite laminates subjected to the various rules constraints. The expert system was realized in the graphic-based design environment. Therefore, users can access and use the system easily. The optimal stacking sequence is obtained by means of integration of a genetic algorithm, finite element analysis. These systems were integrated with the rules of design heuristics under an expert system shell. The optimal stacking sequence combination for the application of interest is drawn from the discrete ply angles and design rules stored in the knowledge base of the expert system. For the integration and management of softwares, a graphic-based design environment that provides multi-tasking and graphic user interface capability is built.

• Transactions of Materials Processing
• /
• v.6 no.3
• /
• pp.203-212
• /
• 1997

In this research, to obtain the optimal die width of CV die(conventional die), which replaces FM die in free forging of large scale rotor using the flat die, the model material experiments and theoretical analysis using three dimensional FEM are performed. The FM die, which was designed to remove Mannesmann's effect at the central part of the ingot, has very bad workabiltity in real field, therefore on the empirical base they use the CV die of wide width in actual working field. In this study, the excellency of CV die is proved quantitively, and the optimal die width of CV die is determined through the model material experiments and theoretical analysis using FEM in the point of effective strain, stresses, and load.

• 한국데이터정보과학회:학술대회논문집
• /
• 2002.06a
• /
• pp.155-167
• /
• 2002

In this paper we consider optimal designs of partially constant-stress life testing which is deviced for three-component mixed systems with the considerably long time. Mixed systems are jointed serial system with parallel system. Test items are run at both use condition and accelerated condition until a specified censoring time. The optimal criterion for the sample-proportion allocated to accelerated condition is to minimized asymptotic variance of the maximum likelihood estimators of the acceleration factor and hazard rates.

• Journal of applied mathematics & informatics
• /
• v.29 no.3_4
• /
• pp.987-1000
• /
• 2011

We show how the dynamic optimization problem with the capital constraint can be reduced to the problem to find an optimal modified claim $\tilde{\psi}H$ where $\tilde{\psi}$ is a randomized test in the static problem. Coherent risk measure is used as risk measure in the $L^{\infty}$ random variable spaces. The paper is written in expository style to some degree. We use an average risk of measure(AVaR), which is a special coherent risk measure, to see how to hedge the modified claim in a complete market model.

• Journal of the military operations research society of Korea
• /
• v.24 no.2
• /
• pp.130-145
• /
• 1998

This paper is concerned with the optimization of a system reliability. Two kinds of the reliability model for optimal allocation of parallel redundancy are considered. The algorithm for solving the optimal redundancy problem is proposed by the use of dynamic programming(DP) method. The problem is approached with a standard DP formulation and the DP algorithm is applied to the model and then the optimal solution is found by the backtracking method. The method is applicable to the models having no constraints or having a cost constraint subject to a specified minimum requirement of the system reliability. A consequence of this study is that the developed computer program package are implemental for the optimization of the system reliability.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.57 no.9
• /
• pp.1563-1571
• /
• 2008

In this paper, dynamics modeling of a PEMFC is performed by electro-chemical equations. The developed PEMFC simulation model is implemented using MATLAB Simulink in order to design an optimal PCS for fuel cell systems. In addition, by use of the developed model as an input source of PCS, the validity of the proposed dynamic characteristic model of the PEMFC is verified by various simulation and experimental results.