• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.93.3-93
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• 2001

We propose the cascade PID type fuzzy control method for a good performance such as robustness. The one of proposed method, the first stage have two input variables of an error and a derivative error, and one output variable, and the next stage have two input variables of the output of first stage and an integral error, and one output variable, have two stages. The other, the first stage has one input of an error, and one output variable, and the second stage have two input of the output of first stage and a derivative error, and one output variable, and the third stage have two input of the output of the second stage and an integer error, and one output variable ...

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1997.10a
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• pp.52-55
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• 1997

In this paper, both the generalization of one artificial variable technique to the general bound problem and the efficient implementation of the technique are suggested. When the steepest-edge method is used as a pricing rule in the simplex method, it is easy to update the reduced cost and the simplex multiplier every iteration. Therefore, one artificial variable technique is more efficient than Wolfe's method in which the reduced cost and simplex multiplier must be recalculated in every iteration. When implementing the one artificial variable technique on the LP problems with the general bound restraints on the variables, an arbitrary basic solution which satisfies the bound restraints is sought first, and the artificial column which adjusts the infeasibility is introduced. The phase one of the simplex method minimizes the one artificial variable. The efficient implementation technique includes the splitting, scaling, storage of the artificial column, and the cure of infeasibility problem.

• Communications for Statistical Applications and Methods
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• v.25 no.3
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• pp.283-296
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• 2018

Ranked set sampling, as introduced by McIntyre (Australian Journal of Agriculture Research, 3, 385-390, 1952), dealt with the estimation of the mean of one population. To deal with two or more variables, different forms of bivariate and multivariate ranked set sampling were suggested. For a technique to be useful, it should be easy to implement in practice. Bivariate ranked set sampling, as introduced by Al-Saleh and Zheng (Australian & New Zealand Journal of Statistics, 44, 221-232, 2002), is not easy to implement in practice, because it requires the judgment ranking of each of the combination of the order statistics of the two characteristics. This paper investigates two modifications that make the method easier to use. The first modification is based on ranking one variable and noting the rank of the other variable for one cycle, and do the reverse for another cycle. The second approach is based on ranking of one variable and giving the second variable the same rank (Concomitant Order Statistic) for one cycle and do the reverse for the other cycle. The two procedures are investigated for an estimation of the means of some well-known distributions. It is show that the suggested approaches can be used in practice and can be more efficient than using SRS. A real data set is used to illustrate the procedure.

• Communications of the Korean Mathematical Society
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• v.37 no.1
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• pp.207-212
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• 2022

In this paper, an interesting integral involving the Ī-function of one variable introduced by Rathie has been derived. Since Ī-function is a very generalized function of one variable and includes as special cases many of the known functions appearing in the literature, a number of integrals can be obtained by reducing the Ī function of one variable to simpler special functions by suitably specializing the parameters. A few special cases of our main results are also discussed.

• Journal of the Korean Regional Science Association
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• v.13 no.2
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• pp.93-118
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• 1997

Main findings of this study are as follows. Time-space model of Korea for urban growth model is established. The variables of space model resulted in job and education, which both are significant at 0.01 level and positive. The effect of job and education on the urban growth are 0.76 and 0.29 respectively in average. the determinants for deciding the influences for job variable are income variable and price-level variable. Income variable contributes 68.66% and the direction is negative while contribution of price-level variable is 29.90% and the direction is positive. The determinants for education variable are income, unemployment and wage difference between university graduates and high school graduates. The contribution and the high school graduates. The contribution and the direction of each variable for education variable are 63.6% and positive for the unemployment variable, 15.99% and negative for the income variable and 13.75% and positive for the wage difference variable. This study in different from previous works in three ways. The first is to establish the time-space model which could consider the time and space factor simultaneously. The second is to build data bases which contain the data of almost every city and every year in Korea during the objective period, which make the analysis continuous. The third is that the general analytic framework for the study is macrosocial one rather than a behavioral one, which means the unit of analysis is the metropolitan community and each city occupies population actively through it's potential power such as jobs, education and so on rather than a city population is the passive result of migration.

• Proceedings of the IEEK Conference
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• 2002.07a
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• pp.686-689
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• 2002

This paper proposes a weighted least-squares(WLS) method for designing variable one-dimensional (1-D) FIR digital filters with simultaneously variable magnitude and variable non-integer phase-delay responses. First, the coefficients of a variable FIR filter are represented as the two-dimensional (2-D) polynomials of a pair of spectral parameters: one is for tuning the magnitude response, and the other is for varying its non-integer phase-delay response. Then the optimal coefficients of the 2-D polynomials are found by minimizing the total weighted squared error of the variable frequency response. Finally, we show that the resulting variable FIR filter can be implemented in a parallel form, which is suitable for high-speed signal processing.

• The Journal of Fisheries Business Administration
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• v.40 no.3
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• pp.169-187
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• 2009

This study analyzes the long and short term effect of exchange rate on the import of Korea's fisheries focussed on main fisheries imported from China. The estimation models consist of the following contents. The first model consists of one dependent variable-import quantity of fisheries imported from China(${IMQ_t}^{CHO}$) and three independent variables-${RP_t}^{CHO}$, $EXC_t$ and $GDP_t$. The second one-one dependent variable-import quantity of fisheries imported from China(${JMQ_t}^{NAG})$ and three independent variables-${RP_t}^{NAG}$, $EX_t$ and $GDP_t$. the third one-one dependent variable-import quantity of fisheries imported from China(${IMQ_t}^{AH}$) and three independent variables-${RP_t}^{AH}$, $EX_t$ and $GDP_t$. the forth one-one dependent variable-import quantity of fisheries imported from China(${IMQ_t}^{KO}$) and three independent variables-${RP_t}^{KO)$, $EX_t$ and $GDP_t$. the last one is made up of one dependent variable-import quantity of fisheries imported from China(${IMQ_t}^{GAL}$) and three independent variables-, ${RP_t}^{GAL}$, $EX_t$ and $GDP_t$. and. The estimation results show that exchange rate of the independent variables are statistically significant in only the first model. The figure is elastic. Especially, the effect of exchange rate in first model is grater than that of the. However, the effect of exchange rate, one of independent variables in the ECM, is not statistically significant.

• Structural Engineering and Mechanics
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• v.18 no.5
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• pp.565-589
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• 2004

The present paper concerns the macroscopic overall description of rheologic properties for steel wire and synthetic fibre cables under variable loading actions according to non-linear creep and/or relaxation theory. The general constitutive equations of non-linear creep and/or relaxation of tension elements - cables under one-step and the variable stress or strain inputs using the product and two types of additive approximations of the kernel functions are presented in the paper. The derived non-linear constitutive equations describe a non-linear rheologic behaviour of the cables for a variable stress or strain history using the kernel functions determined only by one-step - constant creep or relaxation tests. The developed constitutive equations enable to simulate and to predict in a general way non-linear rheologic behaviour of the cables under an arbitrary loading or straining history. The derived constitutive equations can be used for the various tension structural elements with the non-linear rheologic properties under uniaxial variable stressing or straining.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.24 no.10 s.181
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• pp.2477-2486
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• 2000

A planetary gear assembly is a key component to combine and/or split a power from the source. With a planetary gear assembly, a continuously variable unit extends its capacity by means of power bra nching mechanism. Power branching with one planetary gear assembly and one continuously variable unit is categorized into 12 basic types. Each type represents peculiar power transmitting characteristics. Additionally, a multi-mode (range) continuously variable transmission can be designed with accompanying clutches. A multi-mode continuously variable transmission changes the path through which the source power is transmitted. Each path has its own features, such as high efficiency. In this paper, some design principles are examined such as, criteria to guarantee the minimum power efficiency, and constraints to guarantee the smooth mode shift after discussing well-known features of multi-mode M mathematically.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.10a
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• pp.822-825
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• 2004

Continuously variable transmission (CVT) mechanisms considered here is a V-belt drive with two variable-diameter pulleys and effective diameters. One pulley was set by a mechanical link while the other was spring-loaded to provide automatic correspondence. The center distance between the two variable-diameter pulleys was fixed. Experimental studies were executed to analyze efficiencies as change of its speed ratio.