• The Bulletin of The Korean Astronomical Society
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• v.16
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• pp.12.2-12.2
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• 1991

• Journal of dental hygiene science
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• v.11 no.6
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• pp.497-503
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• 2011

The purpose of this study was to examine the effect of a program geared toward improving elderly people's oral function. After a program was provided to the selected elderly people free of charge for three months, they were asked to rate their own oral function to see whether they underwent any changes after their participation in the program, and their oral function was tested to obtain objective data. The collected data were analyzed by the statistical package SPSS WIN 18.0. The findings of the study were as follows: As for changes in their self-rated indicators of oral function, they faced less troubles in most of the oral function items after they participated in the program, and there were statistically significant differences in some of the items. As a result of making an objective evaluation of their oral function, they underwent a little change in salivary flow rate from 1.19 to 1.30, though the change was not statistically significant. In terms of opening, they showed a statistically significant rise of scores from 4.22 to 4.53, and they also showed a statistically significant rise of scores in pronunciation from 30.52 to 38.88. Regarding satisfaction with the program, they gave 4.48 to the program, which implied that they were greatly satisfied with the program. The abovementioned findings suggest that oral health experts and program providers should try to encourage elderly people to keep on taking oral health programs with interest. Currently, oral exercise programs are conducted in some public health centers and in the field of clinical dentistry, and it's required to offer more oral exercise programs as community exercise programs for the elderly.

• Journal of the Korean Data and Information Science Society
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• v.19 no.2
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• pp.587-596
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• 2008

This paper develops the optimal periodic preventive maintenance policies following the expiration of warranty: renewing warranty and non-renewing warranty. After the warranty period is expired, the system undergoes the PM periodically and is minimally repaired at each failure between two successive PMs. Firstly, we determine the expected cost rate per unit time and the expected downtime per unit time for the periodic PM model. Then the overall value function suggested by Jiang and Ji(2002) is applied to obtain the optimal PM period and the optimal PM number. Finally, the numerical examples are presented for illustrative purpose.

• MALSORI
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• no.62
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• pp.149-161
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• 2007

In this paper we proposed a modified reliability function for improving bimodal speaker identification(BSI) performance. The convectional reliability function, used by N. Fox[1], is extended by introducing an optimization factor. We evaluated the proposed method in BSI domain. A BSI system was implemented based on GMM and it was tested using VidTIMIT database. Through speaker identification experiments we verified the usefulness of our proposed method. The experiments showed the improved performance, i.e., the reduction of error rate by 39%.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2001.12a
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• pp.137-140
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• 2001

In this paper, we design 75(Takagi-Sugeno) fuzzy controllers for the systems that can be represented by the 75 fuzzy model. We use inverse optimal approach in which the cost function is determined later than the Lyapunov function and its corresponding control input satisfying the design requirements such as stability and decay rate. The obtained design procedure is in the form of solving LMI(Linear Matrix Inequalities), thus very efficient in practice.

• Proceedings of the KIPE Conference
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• 2011.07a
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• pp.491-493
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• 2011

In this paper, a 15kW grid-connected battery charging and discharging system was proposed. AC regenerative device which consisted of an inverter using IGBTs and LCL filter transferred surplus power to grid. Phase locked loop(PLL) was used to resolve three-phase unbalance. AC regeneration function is able to improve the rate of energy use and the cost savings of energy is expected.

• International Journal of Aeronautical and Space Sciences
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• v.7 no.2
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• pp.33-41
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• 2006

Theoretical-numerical approach of combustion instability in a specific rocket engine is conducted with parametric response functions. Fluctuating instantaneous burning rate is assumed to be functionally coupled with acoustic pressures and have a finite or time-varying amplitudes and phase lags. Only when the amplitudes and phases of combustion response function are sufficiently large and small respectively, the triggered unstable waves are amplified.

• Proceedings of the KIEE Conference
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• 1989.11a
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• pp.505-508
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• 1989

A computer simulation code of UV preionized discharge KrF laser is developed, including time dependent circuit equations, boltzmann equations, and plasma kinetic equations for various atomic and molecular species. Rate constants for electron collision processes are calculated with a boltzmann equations as a function of E/N. In this study, we studied mainly the $KrF^*$ formation process, relaxation process, and the 248nm absorption process as a function of charging voltage.

• 제어로봇시스템학회:학술대회논문집
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• 1986.10a
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• pp.468-470
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• 1986

An optimal control in heat-up operation was formulated for minimizing the quadratic performance criterion which is a function of temperature, temperature gradient in the wall and fuel flow rate. For optimal control law computations mathematical model was simplified with assumptions and then linearized by use of orthogonal collocation in radial direction. Effects of weighting function assigned to temperature and temperature gradient and final time were compared with industrial data.

• Journal of applied mathematics & informatics
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• v.16 no.1_2
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• pp.195-205
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• 2004

To the unconstrained programme of non-convex function, this article give a modified BFGS algorithm. The idea of the algorithm is to modify the approximate Hessian matrix for obtaining the descent direction and guaranteeing the efficacious of the quasi-Newton iteration pattern. We prove the global convergence properties of the algorithm associating with the general form of line search, and prove the quadratic convergence rate of the algorithm under some conditions.