• Proceedings of the Korean Information Science Society Conference
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• 2011.06b
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• pp.313-316
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• 2011

SRAM-based FPGAs are very sensitive to single event upset(SEU) induced by space irradiation. To mitigate SEU effects, space applications employ some mitigation schemes. The triple modular redundancy(TMR) is a well-known mitigation scheme. It uses one or three voters as well as three identical blocks performing the same work. The voters can mask out one error in the outputs from the three replicated blocks. One SEU error in TMRed circuits can be masked but it needs to be detected for some reasons such as to analyze the SEU effects in the satellite or to recover the circuits from the error before additional error occur. In this paper, we developed a fault detection circuit and reporting system to detect a fault on the TMRed circuits. To verify our error detection circuit and reporting circuit, we performed an irradiation test at MC-50 Cyclotron. Experimental results showed that error detection circuit can detect a fault on the TMRed test circuit in radiation environment.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.3 no.1
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• pp.53-56
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• 2010

This paper explains a system that is suitable for detecting software error running on multimedia distance control for transportation safety environment. This system consists of an ED, and ES. ED is an agent that detects an error by hooking techniques for multimedia distance education based on IP-USN gateway software stack environment. ES is an agent that is an error sharing system for multimedia distance control based on IP-USN gateway software stack environment. From the perspective of multimedia collaborative environment, an error application becomes another interactive presentation error is shared with participants engaged in a cooperative work.

• Korean Management Science Review
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• v.12 no.2
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• pp.129-146
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• 1995

As society's relience on computerized information systems to support a wide range of activities proliferates, the long recognized importance for adequate data quality becomes imperative. Furthermore, current trends in information systems such as dispersal of the data resource together with its management have increased the difficulty of maintaining suitable levels of data integrity. Especially, the importance of adequate accounting (transaction) data quality has been long recognized and many procedures (extensive and often elaborate checks and controls) to prevent errors in accounting systems have been introduced and developed. Nevertheless, over time, even in the best maintained systems, deficiencies in stored data will develop. In order to maintain the accuracy and reliability of accounting data at certain level, periodic internal checks and error corrections (internal audits) are required as a part of internal control system. In this paper we develop a general data quality degradation (error accumulation ) and cost model for an account in which we have both error occurrences and error amounts and provide a closed form of optimal audit timing in terms of the number of transactions that should occur before an internal audit should be initiated. This paper also considers the cost- effectiveness of various audit types and different error prevention efforts and suggests how to select the most economical audit type and error prevention method.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.32 no.4C
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• pp.396-400
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• 2007

This paper proposes the fast partial difference elimination (PDE) algorithm. When the conventional PDE cannot skip the rest of matching procedure in a candidate block using a partial matching error, the proposed algorithm estimates to skip it again using the block matching error predicted from the computed partial matching error. The proposed algorithm can eliminate impossible candidate blocks earlier than the conventional PDE since the predicted block matching error is always bigger than the partial matching error. The simulation results show that the proposed algorithm can significantly reduce the computations while keeping image quality as good as the conventional PDE.

• Journal of the Korean Data and Information Science Society
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• v.23 no.6
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• pp.1093-1102
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• 2012

In this paper, we predicted the interest spread using the VAR (vector autoregressive) model. Variables used in the VAR model were selected among 56 domestic and foreign macroeconomic time series through crosscorrelation and Granger causality test. The performance of the VAR model was compared with the univariate time series model, AR (autoregressive) model, in view of MAPE (mean absolute percentage error) and RMSE (root mean square error) of forecasts for the last twelve months.

• 제어로봇시스템학회:학술대회논문집
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• 1995.10a
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• pp.211-214
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• 1995

A precise open-loop positioning system using linear pulse motor has been developed. The system is operated in a microstepping mode by controlling the electric current. One step of 508 .mu.m (tooth pitch of the linear pulse motor) is divided into 508 micro-steps equally. The displacement is measured with a system using a Fiezeau-type interferometer. Periodical positioning error with a period of the tooth pitch was observed in this system. Therefore, the position is corrected using the error. The error is stored into computer in advance, and the microstep current is corrected on basis of the stored data. Although the positioning error of the system without the correction was .+-.4.5 .mu.m, that with the correction was decreased to .+-.1.0 .mu.m.

• The KIPS Transactions:PartB
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• v.13B no.6 s.109
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• pp.607-614
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• 2006

In this paper, we propose an error resilience video coder which uses a hybrid error concealment algorithm. Firstly, the algorithm uses the error concealment with data hiding. If the hiding information is lost, the motion vector of lost macroblock is computed with adaptive selection of adjacent motion vectors and OBMC (Overlapped Block Motion Compensation) is applied with this motion vector. We know our algorithm is more effective in case of continuous GOB. The results show more significant improvement than many temporal concealment methods such as MVRI (Motion Vector Rational Interpolation) or existing error concealment using data hiding.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.6C
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• pp.575-581
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• 2006

In this paper, we first define one-dimensional component symbol error function (ODSEF) from the exact expression of the pairwise error probability of orthogonal space-time block codes (OSTBC). Using the ODSEF and the general bit error probability (BEP) expression for quadrature amplitude modulation (QAM) introduced by Cho and Yoon, the exact closed form expressions for the BEP of linear OSTBCs with QAM in slow-varying Rayleigh fading channel are derived.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.6B
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• pp.548-553
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• 2004

Due to the recent advance in wireless communication technology, it is now more demanding to enjoy the high quality of service in the wireless Internal. TCP, which many Internet applications depend on for the end-to-end transport service, is optimized for the wired environment. Consequently, TCP suffers from severe performance degradation in the wireless environment where the bit error rate is relatively high and the burst errors frequently take place. In this paper, we propose a Robust TCP algorithm, which can effectively react against the burst error and significantly improve the TCP performance in wireless Internet. It is shown through the simulations that the Robust TCP performs well in the wireless environment, especially under the burst error condition.

• Journal of the Korea Society of Computer and Information
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• v.15 no.4
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• pp.57-63
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• 2010

The damping parameter of Levenberg-Marquardt algorithm switches between error backpropagation and Gauss-Newton learning and affects learning speed. Fixing the damping parameter induces some oscillation of error and decreases learning speed. Therefore, we propose the way of a variable damping parameter with referring to the alternation of error. The proposed method makes the damping parameter increase if error rate is large and makes it decrease if error rate is small. This method so plays the role of momentum that it can improve learning speed. We tested both iris recognition and wine recognition for this paper. We found out that this method improved learning speed in 67% cases on iris recognition and in 78% cases on wine recognition. It was also showed that the oscillation of error by the proposed way was less than those of other algorithms.