• Proceedings of the KIEE Conference
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• 2001.07b
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• pp.918-920
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• 2001

PMSM drives are widely used in industrial and residential applications because of high efficiency, high power density and high performance. For better performance of PMSM, however, torque ripples should be reduced. This paper investigates a reduction of torque ripple due to the unsinusoidal flux linkage produced by the shapes of stator slot and magnetic pole. To minimize torque ripple, a simple flux estimator is proposed. This method iteratively compensates the distributed flux linkage from an error between the measured and estimated currents. The proposed algorithm is verified through simulation.

• Proceedings of the KIEE Conference
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• 2006.10c
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• pp.250-252
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• 2006

Due to enhanced high IT (information technology) development, IT-based technology convergences such as IT/ET(electric technology), IT/BT(biology technology) and IT/NT(nano technology) are actively merging trend and their applications spread wide. In this paper PLC (power line communication), one of the merging IT, is investigated as one of the potential IT candidates for IT/ET and IT/BT convergence technology for DLC (direct load control) or bio-medical engineering such as ubiquitous health cares or D2H2 (distributed diagnosis and home health care).

• Proceedings of the KIEE Conference
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• 2005.05a
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• pp.227-229
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• 2005

This paper proposes a method of implementation of digital convergence platform(DCP) which enable the service of broadcasting, communication, multimedia and home automation. Also digital convergence platform based on MPEG-21 multimedia framework can be a model to provide a distributed electronic commerce environment of multimedia and to manage of it. Platform hardware is implemented using a general purpose CPU and high performance digital signal processor and has peripheral units for network and multi I/O. It is able to run applications of multimedia which has variable formats on DSP. In addition, a personal transaction of multimedia packaged with MPEG-21 multimedia framework is provided on digital convergence platform. Like this, digital convergence platform bring up a new architecture of multimedia systems using a new generation network.

• Proceedings of the KSRS Conference
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• 2004.10a
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• pp.509-511
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• 2004

This paper outlines the development of image processing system, which will allow the general users in Government and Public organizations easily to use and apply KOMPSAT EOC images in their own business. The system includes an import/export module of EOC image distributed in Hierarchical Data Format (HDF) file and various image processing analysis modules. Especially, the image mosaic and subset functions are designed to use EOC image as an image map, generating the Ortho-image module. To update the various spatial data with EOC image, some essential modules such as change detection by pattern recognition, overlay between images and vector data, and modification of vector data are implemented in the system. The system is developed based on the user request analysis of government agency, and suited for more efficient use of satellite image in public applications. Such system is expected to contribute to practical application of KOMPSAT-2 that will be launched in 2005. Further efforts will be made to accommodate the KOMPSAT -2 MSC data.

• Communications for Statistical Applications and Methods
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• v.12 no.1
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• pp.19-27
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• 2005

The present paper obtains Bayes estimators for the probability p(Y

• Communications for Statistical Applications and Methods
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• v.6 no.2
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• pp.585-594
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• 1999

Let {$X_{nj}$, 1$\leq$j$\leq$n,j$\geq$1} be a triangular array of random variables which are neither independent nor identically distributed. The almost sure convergences of randomly weighted partial sums of the form $$\sum_n^{j=1}$$ $W_{nj}$$X_{nj} are studied where {Wnj 1$\leq$j$\leq$n, j$\geq$1} is a triangular array of random weights. Application regarding the Efron bootstrap is also introduced.

• Communications for Statistical Applications and Methods
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• v.6 no.1
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• pp.89-98
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• 1999

In this paper we estimate the reliability of parallel system with two components. We assume that the strengths of these components follow bivariate exponential(BVE) models proposed by Marshall-Olkin(1967) Block-Basu(1974) Freund(1961) and Proschan-Sullo(1974) These two components are subjected to a normally distributed random stress which is independent of the strength of the components. If the strengths ($\textit{X}_1$, $\textit{X}_2$) are subjected to a stress($\textit{Y}$) then the system reliability ($\textit{R}$) is given by $\textit{R}=\textit{P}[\textit{Y} We present some numerical results and compare the bias and the mean square error of the maximum likelihood estimator and proposed estimators for a moderate sized samples when $(\textit{X}_1, \textit{X}_2)$ follow BVE of Marshall-Olkin.

• Communications for Statistical Applications and Methods
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• v.16 no.3
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• pp.529-540
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• 2009

In this paper, we present some results on weak laws of large numbers for weighted sums of fuzzy random variables taking values in the space of fuzzy numbers of the real line R. We first give improvements of WLLN for weighted sums of convex-compactly uniformly integrable fuzzy random variables obtained by Joo and Hyun (2005). And then, we consider the case that the averages of expectations of fuzzy random variables converges. As results, WLLN for weighted sums of convexly tight or identically distributed case is obtained.

• Communications for Statistical Applications and Methods
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• v.16 no.3
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• pp.549-556
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• 2009

Let $\{(X_{ni}|1{\leq}i{\leq}n,\;n{\geq}1)\}$ be an array of rowwise negatively associated random variables. In this paper we discuss $n^{{\alpha}p-2}h(n)max_{1{\leq}k{\leq}n}|{\sum}_{i=1}^kX_{ni}|/n^{\alpha}{\rightarrow}0$ completely as $n{\rightarrow}{\infty}$ under not necessarily identically distributed with suitable conditions for ${\alpha}$>1/2, 0${\alpha}p{\geq}1$ and a slowly varying function h(x)>0 as $x{\rightarrow}{\infty}$. In addition, we obtain the complete convergence of moving average process based on negative association random variables which extends the result of Zhang (1996).

• Journal of Korean Society of Industrial and Systems Engineering
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• v.26 no.2
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• pp.62-67
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• 2003

This paper deals with a First-Come, First-Served queueing model to analyze the behavior of heterogeneous finite source system with a single server Each sources and the processor are assumed to operate in independently Markovian environments, respectively. Each request is characterized by its own exponentially distributed source and service time with parameter depending on the state of the corresponding environment, that is, the arrival and service rates are subject to random fluctuations. Our aim is to get the usual stationary performance measures of the system, such as, utilizations, mean number of requests staying at the server, mean queue lengths, average waiting and sojourn times. In the case of fast arrivals or fast service asymptotic methods can be applied. In the intermediate situations stochastic simulation Is used. As applications of this model some problems in the field of telecommunications are treated.