• Title/Summary/Keyword: least-squares

Search Result 2,641, Processing Time 0.024 seconds

Analysis of market share attraction data using LS-SVM (최소제곱 서포트벡터기계를 이용한 시장점유율 자료 분석)

  • Park, Hye-Jung
    • Journal of the Korean Data and Information Science Society
    • /
    • v.20 no.5
    • /
    • pp.879-886
    • /
    • 2009
  • The purpose of this article is to present the application of Least Squares Support Vector Machine in analyzing the existing structure of brand. We estimate the parameters of the Market Share Attraction Model using a non-parametric technique for function estimation called Least Squares Support Vector Machine, which allows us to perform even nonlinear regression by constructing a linear regression function in a high dimensional feature space. Estimation by Least Squares Support Vector Machine technique makes it a good candidate for solving the Market Share Attraction Model. To illustrate the performance of the proposed method, we use the car sales data in South Korea's car market.

  • PDF

Approximated Constrained Least Squares Filter for Real-Time Directionally Adaptive Image Restoration (제약적 최소 제곱 필터의 근사화를 이용한 실시간 방향 적응적 영상복원)

  • Cho, Changhun;Jeon, Jaehwan;Paik, Joonki
    • Journal of the Institute of Electronics and Information Engineers
    • /
    • v.50 no.12
    • /
    • pp.150-158
    • /
    • 2013
  • In this paper we present approximated constrained least squares filter for real-time directionally adaptive image restoration. The proposed method makes a hardware implementation easier for real-time image restoration because of reducing the filter size. Furthermore, for directional adaptive image restoration, this paper estimates the local orientation by analyzing the covariance matrix and applies to approximated constrained least squares filter. Experimental results show that the proposed method is sharper and less artifacts than existing methods.

Iterative Least-Squares Method for Velocity Stack Inversion - Part A: IRLS method (속도중합역산을 위한 반복적 최소자승법 - Part A: IRLS 방법)

  • Ji Jun
    • Geophysics and Geophysical Exploration
    • /
    • v.8 no.2
    • /
    • pp.163-169
    • /
    • 2005
  • Recently, the velocity stack domain is having an attention as a very useful domain for various processing in seismic data processing. In order to be used in many applications, the velocity stack should be obtained through an inversion method and the used inversion should have properties like the robustness to noise and the parsimony of velocity stack result. Iteratively Reweighted Least-Squares (IRLS) method is the one of the inversion methods that have such properties. This paper describes the theoretical background, implementation of the method, and examines the characteristics and limits of the IRLS method.

A Study on the Improvement of the Accuracy for the Least-Squares Method Using Orthogonal Function (직교함수를 이용한 최소자승법의 정밀도 향상에 관한 연구)

  • Cho, Won Cheol;Lee, Jae Joon
    • KSCE Journal of Civil and Environmental Engineering Research
    • /
    • v.6 no.4
    • /
    • pp.43-52
    • /
    • 1986
  • With increasing of computer use, a least squares method is now widely used in the regression analysis of various data. Unreliable results of regression coefficients due to the floating point of computer and problems of ordinary least squares method are described in detail. To improve these problems, a least squares method using orthogonal function is developed. Also, Comparison and analysis are performed through an example of numerical test, and re-orthogonalization method is used to increase the accuracy. As an example of application, the optimum order of AR process for the time series of monthly flow at the Pyungchang station is determined using Akaike's FPE(Final Prediction Error) which decides optimum degree of AR process. The result shows the AR(2) process is optimum to the series at the station.

  • PDF

A Study on the Adjustment of Precise Leveling Nets by the Method of Dynamic Least Squares (동적최소(動的最小)제곱법(法)에 의한 정밀수준강(精密水準綱)의 조정(調整))

  • Lee, Kye Hak;Jang, Ji Won;Kang, Hee Bog;Sung, Soo Lyeon
    • KSCE Journal of Civil and Environmental Engineering Research
    • /
    • v.8 no.2
    • /
    • pp.177-184
    • /
    • 1988
  • The method of least squares has been applied to the static data, but it was not applications for the processing of observed values accompaning real-time variation. In this paper, having been considered all observations to be the function of time, leveling nets were analized dynamically by introducing the concept of time to conventional method of least squares. As a results, the method of dynamic least squares was well applicable to the adjustment of leveling nets.

  • PDF

Influencing factors and prediction of carbon dioxide emissions using factor analysis and optimized least squares support vector machine

  • Wei, Siwei;Wang, Ting;Li, Yanbin
    • Environmental Engineering Research
    • /
    • v.22 no.2
    • /
    • pp.175-185
    • /
    • 2017
  • As the energy and environmental problems are increasingly severe, researches about carbon dioxide emissions has aroused widespread concern. The accurate prediction of carbon dioxide emissions is essential for carbon emissions controlling. In this paper, we analyze the relationship between carbon dioxide emissions and influencing factors in a comprehensive way through correlation analysis and regression analysis, achieving the effective screening of key factors from 16 preliminary selected factors including GDP, total population, total energy consumption, power generation, steel production coal consumption, private owned automobile quantity, etc. Then fruit fly algorithm is used to optimize the parameters of least squares support vector machine. And the optimized model is used for prediction, overcoming the blindness of parameter selection in least squares support vector machine and maximizing the training speed and global searching ability accordingly. The results show that the prediction accuracy of carbon dioxide emissions is improved effectively. Besides, we conclude economic and environmental policy implications on the basis of analysis and calculation.

Recursive Least Squares Run-to-Run Control with Time-Varying Metrology Delays

  • Fan, Shu-Kai;Chang, Yuan-Jung
    • Industrial Engineering and Management Systems
    • /
    • v.9 no.3
    • /
    • pp.262-274
    • /
    • 2010
  • This article investigates how to adaptively predict the time-varying metrology delay that could realistically occur in the semiconductor manufacturing practice. Metrology delays pose a great challenge for the existing run-to-run (R2R) controllers, driving the process output significantly away from target if not adequately predicted. First, the expected asymptotic double exponentially weighted moving average (DEWMA) control output, by using the EWMA and recursive least squares (RLS) prediction methods, is derived. It has been found that the relationships between the expected control output and target in both estimation methods are parallel, and six cases are addressed. Within the context of time-varying metrology delay, this paper presents a modified recursive least squares-linear trend (RLS-LT) controller, in combination with runs test. Simulated single input-single output (SISO) R2R processes subject to various time-varying metrology delay scenarios are used as a testbed to evaluate the proposed algorithms. The simulation results indicate that the modified RLS-LT controller can yield the process output more accurately on target with smaller mean squared error (MSE) than the original RLSLT controller that only deals with constant metrology delays.

Performance Analysis of the Localization Compensation Algorithm for Moving Objects Using the Least-squares Method (최소자승법을 적용한 이동객체 위치인식 보정 알고리즘 성능분석)

  • Jung, Moo Kyung;Lee, Dong Myung
    • The Journal of Korean Institute of Communications and Information Sciences
    • /
    • v.39C no.1
    • /
    • pp.9-16
    • /
    • 2014
  • The localization compensation algorithm for moving objects using the least-squares method is suggested and the performance of the algorithm is analyzed in this paper. The suggested compensation algorithm measures the distance values of the mobile object moving as a constant speed by the TMVS (TWR Minimum Value Selection) method, estimates the location of the mobile node by the trilateration scheme based on the values, and the estimated location is compensated using the least-squares method. By experiments, it is confirmed that the localization performance of the suggested compensation algorithm is largely improved to 58.84% and 40.28% compared with the conventional trilateration method in the scenario 1 and 2, respectively.

A Design of New Digital Adaptive Predistortion Linearizer Algorithm Based on DFP(Davidon-Fletcher-Powell) Method (DFP Method 기반의 새로운 적응형 디지털 전치 왜곡 선형화기 알고리즘 개발)

  • Jang, Jeong-Seok;Choi, Yong-Gyu;Suh, Kyoung-Whoan;Hong, Ui-Seok
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
    • /
    • v.22 no.3
    • /
    • pp.312-319
    • /
    • 2011
  • In this paper, a new linearization algorithm for DPD(Digital PreDistorter) is suggested. This new algorithm uses DFP(Davidon-Fletcher-Powell) method. This algorithm is more accurate than that of the existing algorithms, and this method renew the best-fit value in every routine with out setting the initial value of step-size. In modeling power amplifier, the memory polynomial model which can model the memory effect of the power amplifier is used. And the overall structure of linearizer is based on an indirect learning architecture. In order to verify for performance of proposed algorithm, we compared with LMS(Least Mean-Squares), RLS(Recursive Least squares) algorithm.

Short-Term Wind Speed Forecast Based on Least Squares Support Vector Machine

  • Wang, Yanling;Zhou, Xing;Liang, Likai;Zhang, Mingjun;Zhang, Qiang;Niu, Zhiqiang
    • Journal of Information Processing Systems
    • /
    • v.14 no.6
    • /
    • pp.1385-1397
    • /
    • 2018
  • There are many factors that affect the wind speed. In addition, the randomness of wind speed also leads to low prediction accuracy for wind speed. According to this situation, this paper constructs the short-time forecasting model based on the least squares support vector machines (LSSVM) to forecast the wind speed. The basis of the model used in this paper is support vector regression (SVR), which is used to calculate the regression relationships between the historical data and forecasting data of wind speed. In order to improve the forecast precision, historical data is clustered by cluster analysis so that the historical data whose changing trend is similar with the forecasting data can be filtered out. The filtered historical data is used as the training samples for SVR and the parameters would be optimized by particle swarm optimization (PSO). The forecasting model is tested by actual data and the forecast precision is more accurate than the industry standards. The results prove the feasibility and reliability of the model.