• Title/Summary/Keyword: backward error

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Realization for FF-PID Controlling System with Backward Propagation Algorithm (역전파 알고리즘을 이용한 FF-PID 제어 시스템 구현)

  • Ryu, Jae-Hoon;Hur, Chang-Wu;Ryu, Kwang-Ryol
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2007.06a
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    • pp.171-174
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    • 2007
  • A realization for FF-PID(Feed-Forward PID) controlling system with backward propagation algorithm and image pattern recognition is presented in this paper. The pattern recognition used backward propagation of nervous network is teaming. FF-PID is enhanced the response characteristic of moving image by using the controlling value which is output error for the target value of nervous system. In conclusion of experiment, the system is shown that the response is worked as 2.7sec that is enhanced round 15% in comparison with general difference image algorithm. The system is able to control a moving object with effect.

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Wine Quality Prediction by Using Backward Elimination Based on XGBoosting Algorithm

  • Umer Zukaib;Mir Hassan;Tariq Khan;Shoaib Ali
    • International Journal of Computer Science & Network Security
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    • v.24 no.2
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    • pp.31-42
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    • 2024
  • Different industries mostly rely on quality certification for promoting their products or brands. Although getting quality certification, specifically by human experts is a tough job to do. But the field of machine learning play a vital role in every aspect of life, if we talk about quality certification, machine learning is having a lot of applications concerning, assigning and assessing quality certifications to different products on a macro level. Like other brands, wine is also having different brands. In order to ensure the quality of wine, machine learning plays an important role. In this research, we use two datasets that are publicly available on the "UC Irvine machine learning repository", for predicting the wine quality. Datasets that we have opted for our experimental research study were comprised of white wine and red wine datasets, there are 1599 records for red wine and 4898 records for white wine datasets. The research study was twofold. First, we have used a technique called backward elimination in order to find out the dependency of the dependent variable on the independent variable and predict the dependent variable, the technique is useful for predicting which independent variable has maximum probability for improving the wine quality. Second, we used a robust machine learning algorithm known as "XGBoost" for efficient prediction of wine quality. We evaluate our model on the basis of error measures, root mean square error, mean absolute error, R2 error and mean square error. We have compared the results generated by "XGBoost" with the other state-of-the-art machine learning techniques, experimental results have showed, "XGBoost" outperform as compared to other state of the art machine learning techniques.

Blockwise analysis for solving linear systems of equations

  • Smoktunowicz, Alicja
    • Journal of the Korean Society for Industrial and Applied Mathematics
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    • v.3 no.1
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    • pp.31-41
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    • 1999
  • We investigate some techniques of iterative refinement of solutions of a nonsingular system Ax = b with A partitioned into blocks using only single precision arithmetic. We prove that iterative refinement improves a blockwise measure of backward stability. Some applications of the results for the least squares problem (LS) will be also considered.

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ANALYSIS OF A MESHFREE METHOD FOR THE COMPRESSIBLE EULER EQUATIONS

  • Kim, Yong-Sik;Pahk, Dae-Hyeon
    • Journal of the Korean Mathematical Society
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    • v.43 no.5
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    • pp.1081-1098
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    • 2006
  • Mathematical analysis is made on a mesh free method for the compressible Euler equations. In particular, the Moving Least Square Reproducing Kernel (MLSRK) method is employed for space approximation. With the backward-Euler method used for time discretization, existence of discrete solution and it's $L^2-error$ estimate are obtained under a regularity assumption of the continuous solution. The result of numerical experiment made on the biconvex airfoil is presented.

CONVERGENCE OF FINITE DIFFERENCE METHOD FOR THE GENERALIZED SOLUTIONS OF SOBOLEV EQUATIONS

  • Chung, S.K.;Pani, A.K.;Park, M.G.
    • Journal of the Korean Mathematical Society
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    • v.34 no.3
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    • pp.515-531
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    • 1997
  • In this paper, finite difference method is applied to approximate the generalized solutions of Sobolev equations. Using the Steklov mollifier and Bramble-Hilbert Lemma, a priori error estimates in discrete $L^2$ as well as in discrete $H^1$ norms are derived frist for the semidiscrete methods. For the fully discrete schemes, both backward Euler and Crank-Nicolson methods are discussed and related error analyses are also presented.

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Advanced Error Tracking Algorithm for H.263 (H.263에 적합한 개선된 에러 트래킹 알고리즘)

  • Hyo-seok Lee;Soo-Mok Jung
    • Journal of the Korea Computer Industry Society
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    • v.5 no.1
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    • pp.123-130
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    • 2004
  • In this paper, an advanced error tracking algorithm by using feedback channel was proposed for error resilient transmission. Using this proposed algorithm, the propagation of errors were reduced within the decoded data over bit error prone network. The addresses of corrupted blocks are reported to encoder by decoder. With negative acknowledgments of feedback channel, the encoder can precisely calculate negative acknowledgments and track the propagated errors by examining the backward motion dependency for proper pixel in the current encoding frame. The error-propagation effects can be terminated completely by INTRA refreshing the affected macro-blocks by using proposed error tracking algorithm. By utilizing the selective four-corner error tracking approximation, the error tracking computations of the proposed algorithm is less than that of the algorithm using full pixel without substantial degradation in video quality. The proposed algorithm can track errors rapidly and accurately.

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Thermal Error Modeling of a Horizontal Machining Center Using the Fuzzy Logic Strategy (퍼지논리를 이용한 수평 머시닝 센터의 열변형 오차 모델링)

  • Lee, Jae-Ha;Lee, Jin-Hyeon;Yang, Seung-Han
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.24 no.10 s.181
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    • pp.2589-2596
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    • 2000
  • As current manufacturing processes require high spindle speed and precise machining, increasing accuracy by reducing volumetric errors of the machine itself, particularly thermal errors, is very important. Thermal errors can be estimated by many empirical models, for example, an FEM model, a neural network model, a linear regression model, an engineering judgment model, etc. This paper discusses to make a modeling of thermal errors efficiently through backward elimination and fuzzy logic strategy. The model of a thermal error using fuzzy logic strategy overcomes limitation of accuracy in the linear regression model or the engineering judgment model. It shows that the fuzzy model has more better performance than linear regression model, though it has less number of thermal variables than the other. The fuzzy model does not need to have complex procedure such like multi-regression and to know the characteristics of the plant, and the parameters of the model can be mathematically calculated. Also, the fuzzy model can be applied to any machine, but it delivers greater accuracy and robustness.

An Algorithm to Determine Aerosol Extinction Below Cirrus Cloud from Mie-LIDAR Signals

  • Wang, Zhenzhu;Wu, Decheng;Liu, Dong;Zhou, Jun
    • Journal of the Optical Society of Korea
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    • v.14 no.4
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    • pp.444-450
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    • 2010
  • The traditional approach to inverting aerosol extinction makes use of the assumption of a constant LIDAR ratio in the entire Mie-LIDAR signal profile using the Fernald method. For the large uncertainty in the cloud optical depth caused by the assumed constant LIDAR ratio, an not negligible error of the retrieved aerosol extinction below the cloud will be caused in the backward integration of the Fernald method. A new algorithm to determine aerosol extinction below a cirrus cloud from Mie-LIDAR signals, based on a new cloud boundary detection method and a Mie-LIDAR signal modification method, combined with the backward integration of the Fernald method is developed. The result shows that the cloud boundary detection method is reliable, and the aerosol extinction below the cirrus cloud found by inverting from the modified signal is more efficacious than the one from the measured signal including the cloud-layer. The error due to modification is less than 10% taken in our present example.

An Error Control Algorithm for Wireless Video Transmission based on Feedback Channel (무선 비디오 통신을 위한 피드백 채널 기반의 에러복구 알고리즘의 개발)

  • 노경택
    • Journal of the Korea Society of Computer and Information
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    • v.7 no.2
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    • pp.95-100
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    • 2002
  • By feedback channel, the decoder reports the addresses of corrupted macroblocks induced by transmission errors back to the encoder With these negative acknowledgements, the encoder can make the next frame having propagated errors by using forward dependency based on GOBs and MBs of the frame happening transmission errors. The encoder can precisely calculate and track the propagated errors by examining the backward motion dependency for each of four comer pixels in the current encoding frame until before-mentioned the next frame. The error-propagation effects can be terminated completely by INTRA refreshing the affected macroblocks. Such a fast algorithm further reduce the computation and memory requirements. The advantages of the low computation complexity and the low memory requirement are Particularly suitable for real-time implementation.

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Thermal Error Modeling of a Horizontal Machining Center Using the Fuzzy Logic Strategy (퍼지논리를 이용한 수평 머시닝 센터의 열변형 오차 모델링)

  • 이재하;양승한
    • Proceedings of the Korean Society of Machine Tool Engineers Conference
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    • 1999.05a
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    • pp.75-80
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    • 1999
  • As current manufacturing processes require high spindle speed and precise machining, increasing accuracy by reducing volumetric errors of the machine itself, particularly thermal errors, is very important. Thermal errors can be estimated by many empirical models, for example, an FEM model, a neural network model, a linear regression model, an engineering judgment model etc. This paper discusses to make a modeling of thermal errors efficiently through backward elimination and fuzzy logic strategy. The model of a thermal error using fuzzy logic strategy overcome limitation of accuracy in the linear regression model or the engineering judgment model. And this model is compared with the engineering judgment model. It is not necessary complex process such like multi-regression analysis of the engineering judgment model. A fuzzy model does not need to know the characteristics of the plant, and the parameters of the model can be mathematically calculated. Like a regression model, this model can be applied to any machine, but it delivers greater accuracy and robustness.

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