• Journal of the Korean Society for Industrial and Applied Mathematics
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• v.13 no.4
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• pp.257-265
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• 2009

In this paper we find an explicit form of upper bound of Hausdorff distance between given cubic spline curve and its quadratic spline approximation. As an application the approximation of offset curve of cubic spline curve is presented using our explicit error analysis. The offset curve of quadratic spline curve is exact rational spline curve of degree six, which is also an approximation of the offset curve of cubic spline curve.

• Proceedings of the KIEE Conference
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• 2001.07c
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• pp.1896-1898
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• 2001

An offset problem caused by the static parasitic capacitors is analyzed and then some techniques to reduce their effect on the capacitive position sensor are presented. Also new offset compensation technique is proposed that by adjusting the magnitudes of the modulating signals independently, the charge imbalance between electrodes caused by the parasitic capacitors is eliminated without sensor gain variation. Simulation results are given to validate the proposed compensation technique.

• Proceedings of the IEEK Conference
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• 1999.11a
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• pp.971-974
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• 1999

A offset compensated class A bipolar second-generation current conveyor (CCII) for high-accuracy current-mode signal processing was proposed. The CCII adopts two diode-connection transistor between voltage input and voltage output to reduce offset voltage. Experiments show that the proposed CCII has offset voltage of 0.05 ㎷, input impedance of 2 Ω and the 3-㏈ cutoff frequency of 30 MHz when used a voltage amplifier. The power dissipation is 6 ㎷.

• 제어로봇시스템학회:학술대회논문집
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• 1987.10b
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• pp.214-217
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• 1987

In this paper self tuning control of interconnected systems are dealt in view point of large scale system control. The plant model is given in multiple ARMA process. This process is simplified as independent SISO ARMA process having offset terms. This offset was considered as effects of interconnections. In each decentralized system, self tuning controller with instrumental variable method is adopted. As a result, this algorithm enables the parameter estimation to be unbiased and non-drift. This controller contains a new implicit offset rejection technique. Simulation results considers well with the analysis in case of linear interconnection.

• Proceedings of the KIEE Conference
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• 2015.07a
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• pp.837-838
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• 2015

본 논문에서는 양측식 영구자석 선형 동기 전동기(Permanent Magnet Linear Synchronous Motor: 이하 PMLSM)의 전기자 분산배치를 위해 전기자에 보조치 및 Offset에 의해 나타나는 단부 코깅력을 해석하였다. 또한 가장 낮은 단부 코깅력을 가지는 Offset 위치에 대하여 역기전력을 분석하였으며 이에 따른 추력 특성에 대한 고찰을 수행하였다.

• Communications of the Korean Mathematical Society
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• v.22 no.4
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• pp.641-648
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• 2007

In this paper, we present the exact Hausdorff distance between the offset curve of quadratic $B\'{e}zier$ curve and its quadratic $GC^1$ approximation. To illustrate the formula for the Hausdorff distance, we give an example of the quadratic $GC^1$ approximation of the offset curve of a quadratic $B\'{e}zier$ curve.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1996.11a
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• pp.626-630
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• 1996

The most important problem in NC machining of a freeform mold surface is removal of tool interference. In this paper three methods are introduced to remove self-intersection on offsetted freeform surface for 3-axis NC. All methods are using intersectional offset curves on original offset surface. The fast method is sequential loop check using two lines which have two neighbor points of intersectional offset curves.

• Journal of Communications and Networks
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• v.15 no.3
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• pp.258-265
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• 2013

In this study, we investigate the multi-carrier spread spectrum (MCSS) communication system which adopts the self-encoded spread spectrum in a downlink synchronous channel. It is very difficult to completely eliminate the frequency offset in practical channel scenarios. We demonstrate that the self-encoded MCSS (SE-MCSS) with iterative despreading manifests a remarkable immunity to residual frequency offset. The SE-MCSS can be an excellent candidate for the future generation of wireless services.

• 제어로봇시스템학회:학술대회논문집
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• 1987.10a
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• pp.817-826
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• 1987

An offset-free self-tuning control with pole placement (STCPP) and a recursive parameter estimation with multiple and variable forgetting factors (REWF), together with their application to a real plant, are described. There are two different types of offset-free STCPP; their features are analysed and discussed. REMVF employs as many forgetting factors as parameter estimates. It is suitable when parameters to be estimated are changing at different rates. The offset-free STCPP and REMVF have been successfully applied to a real plant, giving excellent results.

• The Journal of the Korea Contents Association
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• v.9 no.2
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• pp.10-17
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• 2009

This paper analyze the effect of frequency offset for the IEEE 802.15.4b LR-WPAN(Low-Rate Wireless Personal Area Network) with 915MHz bandwidth noncoherent DSSS O-QPSK based receiver system, and presents a compensation method with addition of differential filter to the system for compensation of frequency offset problem. DSSS PSSS-ASK and DSSS O-QPSK modulation techniques are accepted within the regularization of IEEE 802.15.4b. These new method can obtain 250kbps transmission rate. The DSSS O-QPSK modulation method that is used in this paper has no BER variation below 40ppm(frequency offset 36.6kHz), but if the offset frequency become high above 40ppm, then the system cannot have stable receiving condition due to worse BER. To solve this problem, we present a more stabilized receiver system at maximum frequency offset ${\pm}80ppm$ using MDDF unti a correlator of DSSS O-QPSK modulator. Moreover computer simulation results will be presented to evaluate the performance of the proposed algorithm unde various AWGN and frequency offset environment.