• Title/Summary/Keyword: Error Correction Signal

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Experimental Research for Traction force Sensor Development on Drawing Exercise Medical Instrument (재활 및 교정을 위한 견인운동치료기의 견인측정센서 개발에 관한 실험적 연구)

  • Lee, Sang-sik;Park, Won-yeop;Lee, Choong-ho
    • The Journal of Korea Institute of Information, Electronics, and Communication Technology
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    • v.2 no.2
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    • pp.3-8
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    • 2009
  • The traction system has been mainly used for rehabilitation and correction of patients with spine or gait diseases in orthopedics or at home. Some problems could occur in human body when patients forced their training using the traction system. So it needs to measure a traction force and control the training time. However, most of products on market have no sensor measuring traction force. Thus we designed and made a sensor detecting traction force using strain gauge, amplifier for transition to output signal and experiment devices for performance test. We carried out experiment of a sensor detecting a traction force and measured electric responses of it with respect to traction loads. Maximum error was within about 1% for experiments in static condition and the average error was about 0.7% for experiments in dynamic condition. We concluded that it is possible to use the developed sensor for measurement of traction force since the maximum output variation of a sensor detecting a traction force was about 0.3% in $0^{\circ}C-60^{\circ}C$ temperature condition.

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Seismic Weathering Correction Using IRS Approach: A Test to the Synthetic Data of Cheongju Granitic Bodies (IRS(간섭 굴절보정)를 이용한 탄성파 풍화대 보정: 청주 화강암체에 대한 적용)

  • Kang, Yu-Gyeong;Sa, Jin-Hyeon;Kim, Ji-Soo;Kim, Jong-Woo
    • The Journal of Engineering Geology
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    • v.29 no.2
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    • pp.153-162
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    • 2019
  • Rapid variations in the geometry (i.e., thickness) of the refractor and low velocities affect greatly the imaging of the reflectors of land seismic data. Conventional solutions to obtain the weathering models utilizes first break picking method, which requires time consuming steps and causes the human error in picking the first arrivals. A new interferometric approach (interferometric refraction statics, IRS) which utilizes the first arrival signal (S/N enhanced by refraction convolution stack) instead of first break picking, is tested in this study to the synthetic data from the velocity structure provided by surface geophysics (refraction, MASW) and borehole geophysics (tomography, SPS logging) for the Cheongju granitic bodies. The results of IRS approach are found to be better than the ones from conventional first break picking in terms of continuities and horizontal resolution of the reflectors. The unresolved long-wavelength statics in brute stack are much removed by IRS weathering correction and the overlying refractors (the base of shallow weathering zone) are incidentally delineated in the refraction convolution stack.

Determination of the Optimal Aggregation Interval Size of Individual Vehicle Travel Times Collected by DSRC in Interrupted Traffic Flow Section of National Highway (국도 단속류 구간에서 DSRC를 활용하여 수집한 개별차량 통행시간의 최적 수집 간격 결정 연구)

  • PARK, Hyunsuk;KIM, Youngchan
    • Journal of Korean Society of Transportation
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    • v.35 no.1
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    • pp.63-78
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    • 2017
  • The purpose of this study is to determine the optimal aggregation interval to increase the reliability when estimating representative value of individual vehicle travel time collected by DSRC equipment in interrupted traffic flow section in National Highway. For this, we use the bimodal asymmetric distribution data, which is the distribution of the most representative individual vehicle travel time collected in the interrupted traffic flow section, and estimate the MSE(Mean Square Error) according to the variation of the aggregation interval of individual vehicle travel time, and determine the optimal aggregation interval. The estimation equation for the MSE estimation utilizes the maximum estimation error equation of t-distribution that can be used in asymmetric distribution. For the analysis of optimal aggregation interval size, the aggregation interval size of individual vehicle travel time was only 3 minutes or more apart from the aggregation interval size of 1-2 minutes in which the collection of data was normally lost due to the signal stop in the interrupted traffic flow section. The aggregation interval that causes the missing part in the data collection causes another error in the missing data correction process and is excluded. As a result, the optimal aggregation interval for the minimum MSE was 3~5 minutes. Considering both the efficiency of the system operation and the improvement of the reliability of calculation of the travel time, it is effective to operate the basic aggregation interval as 5 minutes as usual and to reduce the aggregation interval to 3 minutes in case of congestion.

Improvement of RTL system for location monitoring of multi-laborers in the underground space (지하공간에서 노무자의 위치 인식을 위한 RTL 시스템 개선)

  • Song, Ki-Il;Lim, Jin-Sun;Lee, Hang-Lo
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.18 no.3
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    • pp.331-339
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    • 2016
  • Real time location (RTL) system which can control the safety of laborers in the underground space is developed in this study. This innovative system can monitor the location and history of movement of multiple laborers in real time. To accommodate constrains of the underground space, the system is portable and composed with low-battery mode. Since conventional method to detect the location of laborer with radio signal strength indicator (RSSI) contains high errors, new measurement system using accelerometers and correction method are suggested in this study. Field test is performed to validate the developed system. The error for moving laborer was 0.4 m and for non-moving laborers was 0.2 m. Thus, it is found that the new RTL system can be used to monitor the location of laborers in the underground construction space.

Performance Analysis of Block Turbo Coded OFDM System Using Channel State Information (채널상태정보를 이용하는 블록터보 부호화된 OFDM 시스템의 성능 분석)

  • Kim, Han-Jong
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.12 no.2
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    • pp.872-877
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    • 2011
  • In this paper, the new decoding algorithm of Block Turbo Codes using Channel State Information(CSI), which is estimated to compensate for the distorted signal caused by multi-path fading, is proposed in order to improve error correction capacity during decoding procedure in OFDM system. The performance of the new decoding algorithm is compared to that of the conventional decoding algorithm without using channel state information under the Rayleigh fading channel. Experimental results showed that in case of only one iteration coding gains of up to 5.0dB~9.0dB can be obtained by applying the channel state information to the conventional decoding algorithm according to the modulation methods. In addition to that, the new decoding algorithm using channel state information at only one iteration shows a performance improvement of 3.5dB to 5.0dB when compared to the conventional decoding algorithm after four iterations. This leads to reduce the considerable amount of computation.

Speech Recognition on Korean Monosyllable using Phoneme Discriminant Filters (음소판별필터를 이용한 한국어 단음절 음성인식)

  • Hur, Sung-Phil;Chung, Hyun-Yeol;Kim, Kyung-Tae
    • The Journal of the Acoustical Society of Korea
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    • v.14 no.1
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    • pp.31-39
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    • 1995
  • In this paper, we have constructed phoneme discriminant filters [PDF] according to the linear discriminant function. These discriminant filters do not follow the heuristic rules by the experts but the mathematical methods in iterative learning. Proposed system. is based on the piecewise linear classifier and error correction learning method. The segmentation of speech and the classification of phoneme are carried out simutaneously by the PDF. Because each of them operates independently, some speech intervals may have multiple outputs. Therefore, we introduce the unified coefficients by the output unification process. But sometimes the output has a region which shows no response, or insensitive. So we propose time windows and median filters to remove such problems. We have trained this system with the 549 monosyllables uttered 3 times by 3 male speakers. After we detect the endpoint of speech signal using threshold value and zero crossing rate, the vowels and consonants are separated by the PDF, and then selected phoneme passes through the following PDF. Finally this system unifies the outputs for competitive region or insensitive area using time window and median filter.

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Color Improvement of Retinex Image Using the Maximum Color Difference Signal Table (최대 색차신호 표를 이용한 Retinex 영상의 컬러 향상)

  • Lee, Jae-Won;Jung, Jee-Hoon;Hong, Sung-Hoon
    • Journal of Broadcast Engineering
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    • v.17 no.5
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    • pp.851-863
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    • 2012
  • Retinex algorithm enhances the contrast of image through visibility improvement. However, the conventional Retinex methods may produces color distortions due to error of hue representation and over-saturation since the methods work in RGB color space. In this paper, we propose a new Retinex algorithm with color correction, which improves contrast by using MSR(Multi-Scale Retinex) working in YCbCr color space and adaptively compensates the color saturation based on the maximum color difference table. Our algorithm maps the color difference signals to the correct gamut to prevent over-saturation phenomenon by considering the correlation between luminance and hue dependent saturation. Simulations results show that the proposed method gives better color improvement compared to the conventional methods.

Accelerated Resting-State Functional Magnetic Resonance Imaging Using Multiband Echo-Planar Imaging with Controlled Aliasing

  • Seo, Hyung Suk;Jang, Kyung Eun;Wang, Dingxin;Kim, In Seong;Chang, Yongmin
    • Investigative Magnetic Resonance Imaging
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    • v.21 no.4
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    • pp.223-232
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    • 2017
  • Purpose: To report the use of multiband accelerated echo-planar imaging (EPI) for resting-state functional MRI (rs-fMRI) to achieve rapid high temporal resolution at 3T compared to conventional EPI. Materials and Methods: rs-fMRI data were acquired from 20 healthy right-handed volunteers by using three methods: conventional single-band gradient-echo EPI acquisition (Data 1), multiband gradient-echo EPI acquisition with 240 volumes (Data 2) and 480 volumes (Data 3). Temporal signal-to-noise ratio (tSNR) maps were obtained by dividing the mean of the time course of each voxel by its temporal standard deviation. The resting-state sensorimotor network (SMN) and default mode network (DMN) were estimated using independent component analysis (ICA) and a seed-based method. One-way analysis of variance (ANOVA) was performed between the tSNR map, SMN, and DMN from the three data sets for between-group analysis. P < 0.05 with a family-wise error (FWE) correction for multiple comparisons was considered statistically significant. Results: One-way ANOVA and post-hoc two-sample t-tests showed that the tSNR was higher in Data 1 than Data 2 and 3 in white matter structures such as the striatum and medial and superior longitudinal fasciculus. One-way ANOVA revealed no differences in SMN or DMN across the three data sets. Conclusion: Within the adapted metrics estimated under specific imaging conditions employed in this study, multiband accelerated EPI, which substantially reduced scan times, provides the same quality image of functional connectivity as rs-fMRI by using conventional EPI at 3T. Under employed imaging conditions, this technique shows strong potential for clinical acceptance and translation of rs-fMRI protocols with potential advantages in spatial and/or temporal resolution. However, further study is warranted to evaluate whether the current findings can be generalized in diverse settings.

An Equalizing for CCI Canceling in MLC NAND Flash Memory (MLC NAND 플래시 메모리의 CCI 감소를 위한 등화기 설계)

  • Lee, Kwan-Hee;Lee, Sang-Jin;Kim, Doo-Hwan;Cho, Kyoung-Rok
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.48 no.10
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    • pp.46-53
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    • 2011
  • This paper presents an equalizer reducing CCI(cell-to-cell interference) in MLC NAND flash memory. The CCI is a critical factor which affects occurring data errors in a cell, when surrounding cells are programed. We derived a characteristic equation for CCI considering write procedure of data that is similar with signal equalizing. The model considers the floating gate capacitance coupling effect, the direct field effect, and programming methods of the MLC NAND flash memory. We verify the proposed equalizer comparing with the measured data of 1-block MLC NAND flash memory. As the simulation result, the equalizer shows an error correction ratio about 60% under 20nm NAND process.

A Study on the Design and Implementation of a DSSS-based MODEM for a Right Termination System(FTS) (대역확산방식 비행종단시스템의 모뎀설계와 구현에 관한 연구)

  • Lim Keumsang;Kim Jaehwan;Cho Hyangduck;Kim Wooshik
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.31 no.2C
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    • pp.175-183
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    • 2006
  • This letter proposes a Direct Sequence Spread Spectrum (DS-SS)-based Flight Termination System(FTS) and show the simulation results and implements the system using FRGAs. The DS-SS FTS has immunity interference signals and the influence of jamming signal. Moreover, a DS-SS FTS can provides effects on an authentication and encryption with spread codes. And the system uses more less power than an analog FM system. We used Reed-Solomon (32, 28) code and triple Data Encryption Standard(3DES) for error correction and data encryption. Also we used counter algorithm for unauthenticated device's attack The spread codes of In-phase channel and Quadrature channel were generated by Gold sequence generators. The system was implemented in Altera APEX20K100E FPGA for the ground system and EPF10K100ARC240-3 for the airborne system.