• Title/Summary/Keyword: Error Reduction

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The Effect of Listening to Music for the Reduction of Unilateral Neglect in Chronic Stroke: A Single Subject Study (음악 감상이 만성기 뇌졸중 환자의 편측무시에 미치는 영향 : 단일대상 연구)

  • Lee, Eun-Young
    • Therapeutic Science for Rehabilitation
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    • v.2 no.2
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    • pp.67-75
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    • 2013
  • Objective : This study aims to investigate the effect of listening to music for the reduction of unilateral neglect in stroke patients. Methods : This study used a single subject (A-B) design for a stroke patient with unilateral neglect. The subject was trained for 12 sessions in total. Unilateral neglect was measured using a line bisection test and catherine bergego scale. Results : The line bisection test showed decreased mean error scores of treatment period(B) compared with baseline period(A). and catherine bergego scale showed slightly decreased total scores of treatment period(B) compared with baseline period(A). Conclusion : The listening to music showed a beneficial effect for the reduction of unilateral neglect.

Analysis of Multi-Pass Wet Wire Drawing Process and Its Application (다단 습식 신선공정 해석 및 적용)

  • Lee S. K.;Kim B. M.
    • Transactions of Materials Processing
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    • v.14 no.8 s.80
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    • pp.689-695
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    • 2005
  • Multi-pass wet wire drawing process is used to produce fine wire in the industrial field. The production of fine wire through multi-pass wet wire drawing process with appropriate dies pass schedule would be impossible without understanding the relationship among many process parameters such as material properties, dies reduction, friction conditions, drawing speed etc However, in the industrial field, dies pass schedule of multi-pass wet wire drawing process has been executed by trial and error of experts. This study investigated the relationship among many process parameters quantitatively to obtain the important process information fur the appropriate pass schedule of multi-pass wet wire drawing process. Therefore, it is possible to predict the many important process parameters of multi-pass wet wire drawing process such as dies reduction, machine reduction, drawing force, backtension force, slip rate, slip velocity rate, power etc. The validity of the analyzed drawing force was verified by FE simulation and multi-pass wet wire drawing experiment. Also, pass redesign was performed based on the analyzed results, and the wire breakage between the original pass schedule and the redesigned pass schedule was compared through experiment.

(Frequency Weighted Reduction Using Iterative Approach of BMI) (BMI의 반복적 해법을 이용한 주파수하중 차수축소)

  • Kim, Yong-Tae;O, Do-Chang;Park, Hong-Bae
    • Journal of the Institute of Electronics Engineers of Korea SC
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    • v.39 no.1
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    • pp.33-41
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    • 2002
  • In this paper, we present a frequency weighted model reduction using LMIs for minimizing the H$\infty$ weighted model error compared with the methods of frequency weighted balanced truncation and frequency weighted Hankel norm approximation. The proposed algorithm, its form is equal to the sufficient condition of performance preserving controller approximation, is based on an iterative two-step LMI scheme induced from bound real lemma. So, it can be applied to the problem of the performance preserving controller approximation. The controller reduction is useful in a practical control design and ensures its easy implementation and high reliability The validity of the proposed algorithm is shown through numerical examples. Additionaly, we extend the proposed algorithm to performance preserving controller approximation by applying to the HIMAT(highly maneuverable aircraft technology) system.

A case study on the theoretical and practical applications of the secondary compression index (2차압축지수의 이론과 적용사례 연구)

  • Kim, Sung-In;Lee, Jae-Weon
    • Proceedings of the Korean Geotechical Society Conference
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    • 2007.09a
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    • pp.363-372
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    • 2007
  • The residual settlement due to difference between predicted and observed settlement is one of the social problems during reclaiming construction in the soft ground having a deep depth such as Busan and Gwangyang province. Prediction error for the secondary compression settlement makes the construction much harder. To examine characteristics of the secondary compression settlement, the secondary compression index is the most important factor. In this study, various empirical methods for determining the secondary compression index are evaluated. And errors applied to the design case practically are also explained. The pre loading method is the only way to reduce the secondary compression settlement and reduction ratio of the secondary compression should be investigated correctly. Hence, research results on the reduction ratio of the secondary compression are analyzed in this paper. Moreover, decrement of the secondary compression index due to over consolidation ratio is examined closely by laboratory consolidation test using clay in the Gwangyang area.

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A Hybrid PAPR Reduction Scheme for Optical Wireless OFDM Communication Systems

  • Abdulkafi, Ayad Atiyah;Alias, Mohamad Yusoff;Hussein, Yaseein Soubhi;Omar, Nazaruddin;Salleh, Mohd Kamarulzamin Bin
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.12 no.3
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    • pp.1136-1151
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    • 2018
  • This paper proposes a new hybrid scheme to decrease the high peak to average power ratio (PAPR) of optical orthogonal frequency division multiplexing (OFDM) signals in visible light communication (VLC) systems. The PAPR causes nonlinear signal distortions and high power requirements for the VLC transmitter (light emitting diode, LED). The proposed method is applicable for both direct current-biased optical OFDM (DCO-OFDM) and asymmetrically clipped optical OFDM (ACO-OFDM). In the proposed scheme, the PTS method is firstly modified to fit both optical OFDM approaches transmission and then combined with signal clipping method for further PAPR reduction and bit error rate (BER) improvement of the VLC system. The performance of hybrid scheme has been evaluated and compared with the original OFDM based VLC system, conventional PTS and clipping methods. The results show that the hybrid scheme outperforms other methods in terms of both the PAPR reduction and BER performance.

A Study on Performance Reduction Characteristics of Digital Wireless Communication by APD (APD 통계 모델에 의한 디지털 무선 통신 성능 저감 특성 연구)

  • Lim, Sung-Jin;Hur, Min-Ho;Kwon, Se-Woong;Yoon, Young-Joon
    • Proceedings of the Korea Electromagnetic Engineering Society Conference
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    • 2003.11a
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    • pp.8-12
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    • 2003
  • To protect digital communications and broadcasting that are expected to be increasingly used at frequencies above 1GHz, there is a need to determine permissible disturbance limits for frequency bands above 1GHz according to indicates that better correlates with interference level in digital systems. The quality of digital communications is expressed in terms of bit error rate(BER) or throughput. In this regard, it has been reported that degradation of BER or throughput can be estimated from the amplitude probability distribution (APD) of disturbance amplitude. Therefore, if the APD can simply be measured with a high accuracy, APD will be an optimal index for the assessment of interference in digital communications. In this paper, we show that a measurement method using statistic model of APD has compatibility about performance reduction estimation of WLAN. And through approach of this inspection, we propose numeral models about interference effects of peak value and time rate of spurious.

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PAPR reduction and Pre-distortion techniques against Non-linear Distortion of Satellite WiBro

  • Shrestha, Robin;Seo, Myung-Hwan;Go, Gyeong-Wan;Lee, Byung-Seub
    • Journal of Satellite, Information and Communications
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    • v.3 no.2
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    • pp.18-25
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    • 2008
  • A major drawback of Orthogonal Frequency Division Multiplexing (OFDM) system is high peak-to-average power ratio (PAPR) of the transmitted signal which introduces inevitable non-linear distortion in the transmission due to the amplifier non-linear property. This causes both in-band distortion and out of band spectrum re-growth. A polynomial based pre-distortion is estimated using the non-linear and inverse non-linear polynomial achieved through the Least Square Error (LSE) method. A new technique of PAPR reduction called 'Phase Realignment' (PR) is proposed which has a optimal effect in improving the BER performance as well as considerable reduction in the PAPR. In this paper we used the PR method along with the 'Peak Clipping' (PC) method is used before the pre-distortion to remove the high peak present in the non constant amplitude of the OFDM signal responsible to drive the amplifier in near saturation region for better performance of the system.

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The Effect of Listening to Music for the Reduction of Unilateral Neglect in Chronic Stroke: A Single Subject Study (음악 감상이 만성기 뇌졸중 환자의 편측무시에 미치는 영향: 단일대상 연구)

  • Lee, Eun-Young
    • Therapeutic Science for Rehabilitation
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    • v.2 no.1
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    • pp.57-65
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    • 2013
  • Objective : This study aims to investigate the effect of listening to music for the reduction of unilateral neglect in stroke patients. Methods : This study used a single subject (A-B) design for a stroke patient with unilateral neglect. The subject was trained for 12 sessions in total. Unilateral neglect was measured using a line bisection test and catherine bergego scale. Results : The line bisection test showed decreased mean error scores of treatment period(B) compared with baseline period(A). and catherine bergego scale showed slightly decreased total scores of treatment period(B) compared with baseline period(A). Conclusion : The listening to music showed a beneficial effect for the reduction of unilateral neglect.

Joint Lattice-Reduction-Aided Precoder Design for Multiuser MIMO Relay System

  • Jiang, Hua;Cheng, Hao;Shen, Lizhen;Liu, Guoqing
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.10 no.7
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    • pp.3010-3025
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    • 2016
  • Lattice reduction (LR) has been used widely in conventional multiple-input multiple-output (MIMO) systems to enhance the performance. However, LR is hard to be applied to the relay systems which are important but more complicated in the wireless communication theory. This paper introduces a new viewpoint for utilizing LR in multiuser MIMO relay systems. The vector precoding (VP) is designed along with zero force (ZF) criterion and minimum mean square error (MMSE) criterion and enhanced by LR algorithm. This implementable precoder design combines nonlinear processing at the base station (BS) and linear processing at the relay. This precoder is capable of avoiding multiuser interference (MUI) at the mobile stations (MSs) and achieving excellent performance. Moreover, it is shown that the amount of feedback information is much less than that of the singular value decomposition (SVD) design. Simulation results show that the proposed scheme using the complex version of the Lenstra--Lenstra--Lovász (LLL) algorithm significantly improves system performance.

Improvement Efficiency of Tunnel Work using Site Surveying System (현장측량시스템을 이용한 터널공사의 효용성 향상)

  • Choi, Seok-Keun;Ahn, Won-Tae
    • Journal of Korean Society for Geospatial Information Science
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    • v.14 no.3 s.37
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    • pp.31-37
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    • 2006
  • The existing tunnel survey method contains many problems of taking much measuring time, increasing construction expenses, and delaying a term of construction. Therefore the site survey system for an improvement efficiency is developed. This system will be able to solve the ewer factor and the problem of curtailment of time and expenditure. In order to solve these problems it connected a measurement equipment and a notebook computer, and developed the system which simultaneously with tunnel measurement it will be able to decide locations and errors from site at real-time. The development or the tunnel survey system minimize the error occurrence as measuring tunnel, and the probability of more or less excavation. Therefore this site survey system leads to the effect of the improvement execution quality of work, the cost reduction and the construction term reduction.

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