• Title/Summary/Keyword: Error level

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Effects of Elastic Taping on the Power and Velocity Error of Rectus Femoris after Muscle Fatigue Occurred (탄력성 테이핑이 근 피로를 적용한 넙다리곧은근의 파워오차와 속도오차에 미치는 영향)

  • Yoon, Junggyu
    • Journal of The Korean Society of Integrative Medicine
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    • v.6 no.1
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    • pp.1-6
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    • 2018
  • Purpose : The purpose of this study was to examine the effects of elastic taping on the power and velocity error of rectus femoris after muscle fatigue occurred. Method : The subjects of this study were 15 healthy students. The Primus RS was used to measure the power and velocity error of rectus femoris after muscle fatigue occurred. The power and velocity error were measured 3 times which are consist of pre-fatigue, after-fatigue and after 24 hours applied elastic tape on rectus femoris. A elastic tape was attached to rectus femoris between the antero inferior iliac spine (AIIS) and the tibia tuberosity. The collected data was analyzed using one-way repeated-measures ANOVA for comparison of the power and velocity error according to the measured time and Pearson test for correlation between the power and velocity error according to the measured time. Level of significance was set at 0.05. Result : No significant differences of the power and velocity error were found between $1^{st}$ and 2nd, 3rd measurements (p>.05). The power and velocity error, after 24 hours, of the applied elastic tape with muscle fatigue was significantly lower than muscle fatigue with no taping(p<.05). No significant correlations were found between the power and velocity error according to the measured time(p>.05). Conclusion : After applying the elastic tape on the rectus femoris, muscle fatigue occurred, which improved proprioception by decreasing movement error. It will be an important intervention to prevent musculoskeletal injuries and to enhance the motor control in exercise.

UEP Effect Analysis of LDPC Codes for High-Quality Communication Systems (고품질 통신 시스템을 위한 LDPC 부호의 UEP 성능 분석)

  • Yu, Seog Kun;Joo, Eon Kyeong
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.38A no.6
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    • pp.471-478
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    • 2013
  • Powerful error control and increase in the number of bits per symbol should be provided for future high-quality communication systems. Each message bit may have different importance in multimedia data. Hence, UEP(unequal error protection) may be more efficient than EEP(equal error protection) in such cases. And the LDPC(low-density parity-check) code shows near Shannon limit error correcting performance. Therefore, the effect of UEP with LDPC codes is analyzed for high-quality message data in this paper. The relationship among MSE(mean square error), BER(bit error rate) and the number of bits per symbol is analyzed theoretically. Then, total message bits in a symbol are classified into two groups according to importance to prove the relationship by simulation. And the UEP performance is obtained by simulation according to the number of message bits in each group with the constraint of a fixed total code rate and codeword length. As results, the effect of UEP with the LDPC codes is analyzed by MSE according to the number of bits per symbol, the ratio of the message bits, and protection level of the classified groups.

A Study on Stochastic Simulation Models to Internally Validate Analytical Error of a Point and a Line Segment (포인트와 라인 세그먼트의 해석적 에러 검증을 위한 확률기반 시뮬레이션 모델에 관한 연구)

  • Hong, Sung Chul;Joo, Yong Jin
    • Spatial Information Research
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    • v.21 no.2
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    • pp.45-54
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    • 2013
  • Analytical and simulation error models have the ability to describe (or realize) error-corrupted versions of spatial data. But the different approaches for modeling positional errors require an internal validation that ascertains whether the analytical and simulation error models predict correct positional errors in a defined set of conditions. This paper presents stochastic simulation models of a point and a line segm ent to be validated w ith analytical error models, which are an error ellipse and an error band model, respectively. The simulation error models populate positional errors by the Monte Carlo simulation, according to an assumed error distribution prescribed by given parameters of a variance-covariance matrix. In the validation process, a set of positional errors by the simulation models is compared to a theoretical description by the analytical error models. Results show that the proposed simulation models realize positional uncertainties of the same spatial data according to a defined level of positional quality.

PWM for Single Phase Inverter with 4 - Level Output (4 - 레벨 출력을 갖는 단상 인버어터의 PWM)

  • Jang, Hyun-Soo;Chin, Myung-Churl;Lee, Kwang-Won
    • Proceedings of the KIEE Conference
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    • 1989.07a
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    • pp.527-530
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    • 1989
  • In order to reduce harmonic contents in the inverter output, various PWM ( pulse with modulation ) techniques have been utilized. This paper suggests a single phase inverter with 4-level output and its PWM control scheme. The proposed 4-level output inverter shows better performence than the 3-level output one in respects of the current error and the switching frequency.

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A Fast Motion Estimation Algorithm Based on Multi-Resolution Frame Structure (다 해상도 프레임 구조에 기반한 고속 움직임 추정 기법)

  • Song, Byung-Cheol;Ra, Jong-Beom
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.37 no.5
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    • pp.54-63
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    • 2000
  • We present a multi-resolution block matching algorithm (BMA) for fast motion estimation At the coarsest level, a motion vector (MV) having minimum matching error is chosen via a full search, and a MV with minimum matching error is concurrently found among the MVs of the spatially adjacent blocks Here, to examine the spatial MVs accurately, we propose an efficient method for searching full resolution MV s without MV quantization even at the coarsest level The chosen two MV s are used as the initial search centers at the middle level At the middle level, the local search is performed within much smaller search area around each search center If the method used at the coarsest level is adopted here, the local searches can be done at integer-pel accuracy A MV having minimum matching error is selected within the local search areas, and then the final level search is performed around this initial search center Since the local searches are performed at integer-pel accuracy at the middle level, the local search at the finest level does not take an effect on the overall performance So we can skip the final level search without performance degradation, thereby the search speed increases Simulation results show that in comparison with full search BMA, the proposed BMA without the final level search achieves a speed-up factor over 200 with minor PSNR degradation of 02dB at most, under a normal MPEG2 coding environment Furthermore, our scheme IS also suitable for hardware implementation due to regular data-flow.

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An Adaptive Decoding Algorithm Using the Differences Between Level Radii for MIMO Systems (다중 송수신 안테나 시스템에서 단계별 반경의 차이를 이용한 적응 복호화 알고리즘)

  • Kim, Sang-Hyun;Park, So-Ryoung
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.35 no.7C
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    • pp.618-627
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    • 2010
  • In this paper, we propose an adaptive K-best algorithm in which the number K of candidates is changed according to the differences of level radii. We also compare the bit error performance and complexity of the proposed algorithm with those of several conventional K-best algorithms, where the complexity is defined as the total number of candidates of which partial Euclidean distances have to be calculated. The proposed algorithm adaptively decides K at each level by eliminating the symbols, whose differences of radii are larger than a threshold, from the set of candidates, and the maximum or average value of differences can be adopted as the threshold. The proposed decoding algorithm shows the better bit error performance and the lower complexity than a conventional K-best decoding algorithm with a constant K, and also has a similar bit error performance and the lower complexity than other adaptive K-best algorithms.

Groundwater Level Prediction Using ANFIS Algorithm (ANFIS 알고리즘을 이용한 지하수수위 예측)

  • Bak, Gwi-Man;Bae, Young-Chul
    • The Journal of the Korea institute of electronic communication sciences
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    • v.14 no.6
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    • pp.1235-1240
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    • 2019
  • It is well known that the ground water level changes rapidly before and after the earthquake, and the variation of ground water level prediction is used to predict the earthquake. In this paper, we predict the ground water level in Miryang City using ANFIS algorithm for earthquake prediction. For this purpose, this paper used precipitation and temperature acquired from National Weather Service and data of underground water level from Rural Groundwater Observation Network of Korea Rural Community Corporation which is installed in Miryang city, Gyeongsangnam-do. We measure the prediction accuracy using RMSE and MAPE calculation methods. As a result of the prediction, the periodic pattern was predicted by natural factors, but the change value of ground water level was changed by other variables such as artificial factors that was not detected. To solve this problem, it is necessary to digitize the ground water level by numerically quantifying artificial variables, and to measure the precipitation and pressure according to the exact location of the observation ball measuring the ground water level.

Design and Implementation of IoT-Based Intelligent Platform for Water Level Monitoring (IoT 기반 지능형 수위 모니터링 플랫폼 설계 및 구현)

  • Park, Jihoon;Kang, Moon Seong;Song, Jung-Hun;Jun, Sang Min
    • Journal of Korean Society of Rural Planning
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    • v.21 no.4
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    • pp.177-186
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    • 2015
  • The main objective of this study was to assess the applicability of IoT (Internet of Things)-based flood management under climate change by developing intelligent water level monitoring platform based on IoT. In this study, Arduino Uno was selected as the development board, which is an open-source electronic platform. Arduino Uno was designed to connect the ultrasonic sensor, temperature sensor, and data logger shield for implementing IoT. Arduino IDE (Integrated Development Environment) was selected as the Arduino software and used to develop the intelligent algorithm to measure and calibrate the real-time water level automatically. The intelligent water level monitoring platform consists of water level measurement, temperature calibration, data calibration, stage-discharge relationship, and data logger algorithms. Water level measurement and temperature calibration algorithm corrected the bias inherent in the ultrasonic sensor. Data calibration algorithm analyzed and corrected the outliers during the measurement process. The verification of the intelligent water level measurement algorithm was performed by comparing water levels using the tape and ultrasonic sensor, which was generated by measuring water levels at regular intervals up to the maximum level. The statistics of the slope of the regression line and $R^2$ were 1.00 and 0.99, respectively which were considered acceptable. The error was 0.0575 cm. The verification of data calibration algorithm was performed by analyzing water levels containing all error codes in a time series graph. The intelligent platform developed in this study may contribute to the public IoT service, which is applicable to intelligent flood management under climate change.

Development of MATLAB GUI Based Software for Analysis of KASS Availability Performance (KASS 가용성 성능 평가를 위한 MATLAB GUI 기반 소프트웨어 설계)

  • Choi, Bong-kwan;Han, Deok-hwa;Kim, Dong-uk;Kim, Jung-beom;Kee, Chang-don
    • Journal of Advanced Navigation Technology
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    • v.22 no.5
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    • pp.384-390
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    • 2018
  • This paper introduces a MATLAB graphical user interface (GUI) based software for analysis of korea augmentation satellite system (KASS) availability performance. This software uses minimum variance (MV) estimator and Kriging algorithm to generate integrity information such as user differential range error (UDRE) and grid ionospheric vertical error (GIVE). The information is offered to ground and aviation users in Korean region. The software also gives accuracy data, protection level data and availability map about each user position by using the integrity information. In particular the software calculates the protection level along a path of aircraft. We verified the result of protection level of aviation user by comparing them with the results of SBASimulator#2, which is a simulation tool of european geostationary navigation overlay service (EGNOS). As a result, the protection level error between the result of our software and the SBASimulator#2 was about 2% which means that the result of our software is accurate.

Improvement of multi layer perceptron performance using combination of gradient descent and harmony search for prediction of ground water level (지하수위 예측을 위한 경사하강법과 화음탐색법의 결합을 이용한 다층퍼셉트론 성능향상)

  • Lee, Won Jin;Lee, Eui Hoon
    • Journal of Korea Water Resources Association
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    • v.55 no.11
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    • pp.903-911
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    • 2022
  • Groundwater, one of the resources for supplying water, fluctuates in water level due to various natural factors. Recently, research has been conducted to predict fluctuations in groundwater levels using Artificial Neural Network (ANN). Previously, among operators in ANN, Gradient Descent (GD)-based Optimizers were used as Optimizer that affect learning. GD-based Optimizers have disadvantages of initial correlation dependence and absence of solution comparison and storage structure. This study developed Gradient Descent combined with Harmony Search (GDHS), a new Optimizer that combined GD and Harmony Search (HS) to improve the shortcomings of GD-based Optimizers. To evaluate the performance of GDHS, groundwater level at Icheon Yullhyeon observation station were learned and predicted using Multi Layer Perceptron (MLP). Mean Squared Error (MSE) and Mean Absolute Error (MAE) were used to compare the performance of MLP using GD and GDHS. Comparing the learning results, GDHS had lower maximum, minimum, average and Standard Deviation (SD) of MSE than GD. Comparing the prediction results, GDHS was evaluated to have a lower error in all of the evaluation index than GD.