• Journal of the Korean Data and Information Science Society
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• v.16 no.2
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• pp.371-382
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• 2005

The paper compares the performance of some widely used Bayesian estimators such as Bayes estimator, empirical Bayes estimator, constrained Bayes estimator and constrained Bayes estimator by means of a new measurement under squared error loss function for the typical normal-normal situation. The proposed measurement is a weighted sum of the precisions of first and second moments. As a result, one can gets the criterion according to the size of prior variance against the population variance.

• Journal of the Korean Data and Information Science Society
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• v.21 no.2
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• pp.379-385
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• 2010

This paper considers Bayesian approach to modeling a flexible regression function under functional measurement error model. The regression function is modeled based on semiparametric regression with penalized splines. Model fitting and parameter estimation are carried out in a hierarchical Bayesian framework using Markov chain Monte Carlo methodology. Their performances are compared with those of the estimators under functional measurement error model without semiparametric component.

• Journal of the Korean Institute of Telematics and Electronics B
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• v.32B no.11
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• pp.1464-1472
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• 1995

In this paper, we propose an error diffusion image halftoning technique based on the noise spectrum shaping. The new technique can arbitrarily control the shape of the display error spectrum whereas conventional halftoning algorithms have been known to minimize dc errors only in which case edge information cannot be properly rendered. As a method for estimating the error diffusion coefficients, a least mean square (LMS) approach is adopted.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.1 no.1
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• pp.66-78
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• 1991

In this paper, this paper, the stream cipher systems and the error propagation are analyzed. During the ciphertext transmission. for the error control of errors occurred in the channel, the DSEC(31, 27) RS codes will be used for bothe internal and external error controls for the self-synchromizing cipher system with ciphertext feedback.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.8 no.1
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• pp.12-17
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• 2015

This paper describes an error synchronization running on IP-USN gateway software stack for transportation safety service. This system consists of an TS_EDA, and TS_ESA. TS_EDA is an agent that detects an error for multimedia distance system based on IP-USN gateway software stack environment. TS_ESA is an agent that is an error synchronization system for multimedia distance control based on IP-USN gateway software stack environment. From the perspective of multimedia collaborative environment of IP-USN gateway software stack for transportation safety service, an error application becomes another interactive presentation error is synchronized with participants engaged in a cooperative work.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.42 no.10 s.340
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• pp.29-34
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• 2005

The maximum quantization error has serious effect on the performance of fixed-width multipliers that receive W-bit inputs and produce W-bit products. In this paper, we analyze the error bound of fixed-width modified Booth multipliers. Then, the estimation method for the number of additional columns for fixed-width multipliers is proposed to limit the maximum quantization error within a desired bound. In addition, it is shown that our methodology can be extended to reduced-width multipliers. By simulations, it is shown that the proposed error analysis method is useful to the practical design of fixed-width modified Booth multipliers.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.39A no.5
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• pp.237-243
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• 2014

In this paper, a calculation-efficient method for weight update in the algorithm based on maximization of the zero-error probability (MZEP) is proposed. This method is to utilize the current slope value in calculation of the next slope value, replacing the block processing that requires a summation operation in a sample time period. The simulation results shows that the proposed method yields the same performance as the original MZEP algorithm while significantly reducing the computational time and complexity with no need for a buffer for error samples. Also the proposed algorithm produces faster convergence speed than the algorithm that is based on the error-entropy minimization.

• 한국방재학회:학술대회논문집
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• 2008.02a
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• pp.97-100
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• 2008

This study estimated the error involved in the areal average rainfall derived incomplete radar information due to radar partial coverage of a basin or sub-basin. This study considers the Han River Basin as an application example for the rainfall observation using the Ganghwa rain radar. Among the total of 24 mid-sized sub-basins of the Han River Basin evaluated in this study, only five sub-basins are fully covered by the radar and three are totally uncovered. Remaining 16 sub-basins are partially covered by the radar leading incomplete radar information available. When only partial radar information is available, the sampling error decreases proportional to the size of the radar coverage, which also varies depending on the number of clusters. It is general that smaller sampling error can be expected when the number of clusters increases if the total area coverage remains the same. This study estimated the sampling error of the areal average rainfall of partially-covered mid-sized sub-basins of the Han River Basin, and the results show that the sampling error could be at least several % to maximum tens % depending on the relative coverage area.

• Journal of Information Processing Systems
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• v.8 no.4
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• pp.739-748
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• 2012

We propose an analytic model to compute the station's saturated throughput and packet delay performance of the IEEE 802.11 DCF (Distributed Coordination Function) in which frame transmission error rates in the channel are different from each other. Our analytic model shows that a station experiencing worse frame error rates than the others suffers severe performance degradation below its deserved throughput and delay performance. 802.11 DCF adopts an exponential back-off scheme. When some stations suffer from high frame error rates, their back-off stages should be increased so that others get the benefit from the smaller collision probabilities. This impact is then recursively applied to degrade the performance of the victim stations. In particular, we show that the performance is considerably degraded even if the frame error rate of the victim station satisfies the receiver input level sensitivity that has been specified in the IEEE 802.11 standard. We also verify the analytic results by the OPNET simulations.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.15 no.5
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• pp.364-373
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• 1990

When digital filters are implemented on a computer or with spectial purpose hardware, they unavoidably suffer from errors due to finite wordlength implementation. These errors are classified into coefficient quantiz ation error and roundoff error. The synthesizing method for realizations with minimum coefficient quantization error and minimum roundoff error has been studied. In this paper, it is shown that there is an equivalent transform relation between realizations with minimum coefficient quatization error and minimum roundoff error. To show tha validity of this equivalent transform, we derived the 2nd order digital filter with minimum coefficient quantization error from the 2nd order digital filter with minimum roundoff error and proved the efficiency of realization with minimum coefficient quantization error by simulation.