• Title/Summary/Keyword: least squares estimate

Search Result 273, Processing Time 0.021 seconds

Depth Video Coding Method for Spherical Object (구형 객체의 깊이 영상 부호화 방법)

  • Kwon, Soon-Kak;Lee, Dong-Seok;Park, Yoo-Hyun
    • Journal of Korea Society of Industrial Information Systems
    • /
    • v.21 no.6
    • /
    • pp.23-29
    • /
    • 2016
  • In this paper, we propose a method of depth video coding to find the closest sphere through the depth information when the spherical object is captured. We find the closest sphere to the captured spherical object using method of least squares in each block. Then, we estimate the depth value through the found sphere and encode the depth video through difference between the measured depth values and the estimated depth values. Also, we encode factors of the estimated sphere with encoded pixels within the block. The proposed method improves the coding efficiency up to 81% compared to the conventional DPCM method.

Performance Evaluation of Radial Error of a Rotary Table at Five-axis Machine Tool (5축 공작기계에서 회전 테이블의 반경 오차 성능 평가)

  • Lee, Kwang-Il;Yang, Seung-Han
    • Journal of the Korean Society of Manufacturing Technology Engineers
    • /
    • v.21 no.2
    • /
    • pp.208-213
    • /
    • 2012
  • In this paper, the radial error of a rotary table at five-axis machine tool is evaluated by utilizing ISO 230-2 and estimation method using double ball-bar. The geometric error of a rotary table is defined as position dependent geometric errors or position independent geometric errors according to their physical character. Then estimation method of geometric errors using double ball-bar is simply summarized including measurement path, parametric modeling and least squares approach. To estimate representative radial error, offset error, set-up error which affect to the double ball-bar data, mean value of measured data including CCW/CW-direction are used at estimation process. Radial errors are separated from measured data and used for evaluation with ISO 230-2. Finally, suggested evaluation method is applied to a rotary table at five-axis machine tool and its result is analyzed to improve the accuracy of the rotary table.

An Analysis on the Effect of the Government R&D Subsidies on the Private R&D Investments : in the Case of the Pharmaceutical Industry (정부 R&D 지원의 기업 R&D 투자에 대한 효과 분석 -제약산업을 중심으로-)

  • SaKong, Jin;Shin, You-Won
    • Health Policy and Management
    • /
    • v.20 no.1
    • /
    • pp.183-203
    • /
    • 2010
  • The purpose of this study is to analyze the effect of the R&D subsidies by the government on the private firms' R&D investments in the Korean pharmaceutical industry, which are supposed to have positive effects on their economic performance. We also estimate the relationship between the private firms' R&D investments and firms' economic outcome. Empirical analysis is done by Error Component 2 Stage Least Squares(EC2SLS) estimation using 43 pharmaceutical firms' 8 years' panel data. The elasticity of the government R&D subsidies on the private R&D investments is 0.021%, which we cannot say 'efficient'. Also R&D investments have positive effects on the economic outcome of the pharmaceutical firms, as we expected. We propose several suggestions in the conclusion for the efficient way of government R&D subsidies to induce more private R&D investments.

Export Performance and Stock Return: A Case of Fishery Firms Listing in Vietnam Stock Markets

  • VO, Quy Thi
    • The Journal of Asian Finance, Economics and Business
    • /
    • v.6 no.4
    • /
    • pp.37-43
    • /
    • 2019
  • The research aims to study the relationship between export performance and stock return of Vietnamese fishery companies. To conduct this study, quarterly data was collected for period from 2010-2018 of 13 fishery companies listing in Ho Chi Minh Stock Exchange (HOSE) and Ha Noi Stock Exchange (HNX). The export performance was measured by export intensity, export growth and export market coverage. In addition, interest rate, exchange rate, GDP, firm size, profitability, and financial leverage were considered as the control variables in the research model. Panel data analysis with Generalized Least Squares model was employed to estimate the predictive regression. The findings indicated that export intensity and export growth have a significant and positive relationship with stock returns. However, export market coverage has not a significant relationship with stock return at the 0.05 level. Profitability, financial leverage, and exchange rate have a positive relationship, while interest rate and GDP have no relation to stock return at the 0.05 significance level. The findings imply that investors should consider the export intensity instead of export growth and export market coverage as selecting stock of fishery exports firms to invest; managers should increase export intensity to increase company's stock price or firm market value.

System Improvement Strategy by User Satisfaction Index Model Development and Measurement of Information System (정보시스템 이용자 만족지수 모델 개발 및 측정을 통한 시스템 개선방안)

  • Park, Yong-Jae;Lee, Sang-Hwan;Kwak, Seung-Jin
    • Journal of the Korean Society for information Management
    • /
    • v.24 no.4
    • /
    • pp.173-189
    • /
    • 2007
  • By measuring satisfaction index of the users of Information System, it is possible not only to estimate ROI(Return on Investment) but also to draw the device for the efficiency and improvement of the System. This study tries to give User Satisfaction Index Model for the System, and present operators and managers of the system with the method for improving satisfaction and efficiency by measuring the User Satisfaction Index of representative information systems. For this, the survey was carried out for the representative information systems. On the basis of the analysis, Satisfaction Index was drawn and through Matrix Analysis, the strategy for system improvement was derived.

Bathymetric mapping in Dong-Sha Atoll using SPOT data

  • Huang, Shih-Jen;Wen, Yao-Chung
    • Proceedings of the KSRS Conference
    • /
    • v.2
    • /
    • pp.525-528
    • /
    • 2006
  • The remote sensing data can be used to calculate the water depth especially in the clear and shallow water area. In this study, the SPOT data was used for bathymetric mapping in Dong-Sha atoll, located in northern South China Sea. The in situ sea depth was collected by echo sounder as well. A global positioning system was employed to locate the accurate sampling points for sea depth. An empirical model between measurement sea depth and band digital count was determined and based on least squares regression analysis. Both non-classification and unsupervised classification were used in this study. The results show that the standard error is less than 0.9m for non-classification. Besides, the 10% error related to the measurement water depth can be satisfied for more than 85% in situ data points. Otherwise, the 10% relative error can reach more than 97%, 69%, and 51% data points at class 4, 5, and 6 respectively if supervised classification is applied. Meanwhile, we also find that the unsupervised classification can get more accuracy to estimate water depth with standard error less than 0.63, 0.93, and 0.68m at class 4, 5, and 6 respectively.

  • PDF

Segmentation of Measured Point Data for Reverse Engineering (역공학을 위한 측정점의 영역화)

  • 양민양;이응기
    • Korean Journal of Computational Design and Engineering
    • /
    • v.4 no.3
    • /
    • pp.173-179
    • /
    • 1999
  • In reverse engineering, when a shape containing multi-patched surfaces is digitized, the boundaries of these surfaces should be detected. The objective of this paper is to introduce a computationally efficient segmentation technique for extracting edges, ad partitioning the 3D measuring point data based on the location of the boundaries. The procedure begins with the identification of the edge points. An automatic edge-based approach is developed on the basis of local geometry. A parametric quadric surface approximation method is used to estimate the local surface curvature properties. the least-square approximation scheme minimizes the sum of the squares of the actual euclidean distance between the neighborhood data points and the parametric quadric surface. The surface curvatures and the principal directions are computed from the locally approximated surfaces. Edge points are identified as the curvature extremes, and zero-crossing, which are found from the estimated surface curvatures. After edge points are identified, edge-neighborhood chain-coding algorithm is used for forming boundary curves. The original point set is then broke down into subsets, which meet along the boundaries, by scan line algorithm. All point data are applied to each boundary loops to partition the points to different regions. Experimental results are presented to verify the developed method.

  • PDF

Iterative Polynomial Fitting Technique for the Nonlinear Array Shape Estimation (비선형 선배열 형상 추정을 위한 반복 다항 근사화 기법)

  • 조요한;조치영;서희선
    • The Journal of the Acoustical Society of Korea
    • /
    • v.20 no.8
    • /
    • pp.74-80
    • /
    • 2001
  • Because of ocean waves, swell, steering corrections, etc, the hydrophones of a towed array will not live along a straight line. However the degradation of bearing estimation performance occurs when beamforming is carried out on the hydrophone outputs of an acoustic towed array which is not straight. So it is required to estimate the shape of the array for the improved beamformer output. In this paper, an iterative array shape estimation technique is presented, which is based on the use of the least squares polynomial fitting to the data from heading sensors. The estimation error and the influence of deformations on the performance of the conventional beamformer output are investigated. Finally, the suggested method is applied to the real system in order to investigate the applicability.

  • PDF

Impact of Board Characteristics on Bank Risk: The Case of Vietnam

  • TRAN, Tu T.T.;DO, Nhung H.;NGUYEN, Yen T.
    • The Journal of Asian Finance, Economics and Business
    • /
    • v.7 no.9
    • /
    • pp.377-388
    • /
    • 2020
  • The research identifies hypotheses evaluating the impact of board characteristics on the risk of the commercial bank as well as examining the determinants of bank risk in Vietnam over a 10-year period, starting from 2008. Also, in this research, the differences between the roles of women and men in decision-making are tested. Based on this decision, risks of the banks may arise. Ordinary least squares(OLS) regression, Random effect method, and Fixed effect method are used to estimate the factors that have an impact on bank risk for dataset of all commercial banks in Vietnam. The results found that equity-to-asset ratio, bank performance and the economic growth have an inverse relationship with bank risk, while the size of bank has a positive relationship with the bank risk. One of the highlights of this paper is a demonstration of the relationship between CEO's gender and bank risk. The test result shows that the bank led by a female faces a higher overall risk level and credit risk than a bank led by a male. Based on this result, the paper also makes recommendations to Government, the State Bank of Vietnam and the commercial banks for effective risk management.

Estimation of Crossbreeding Parameters for Serum Lysozyme Level in Broiler

  • Nath, M.;Singh, B.P.;Saxena, V.K.;Dev Roy, A.K.;Singh, R.V.
    • Asian-Australasian Journal of Animal Sciences
    • /
    • v.15 no.2
    • /
    • pp.166-171
    • /
    • 2002
  • The main objective of the present study is to estimate the crossbreeding parameters in respect to serum lysozyme level in broilers. The experiment involved a complete $4{\times}4$ diallel design using four synthetic broiler lines namely Coloured Synthetic Male Line (CSML), White Synthetic Male Line (WSML), Coloured Synthetic Female Line (CSFL) and Naked Neck Line (NNL). The lyophilised Micrococcus lysodeikticus suspension was used to detect the lysozyme level in the serum of birds. The data were analysed by least-squares method to find the effects of genetic and non-genetic factors using appropriate model. The crossbreeding parameters for this trait were estimated by complete diallel model assuming the effect of each synthetic line as fixed. The results indicated that additive and non-additive genetic variation attributed to minor genes at many loci is important for the genetic control of serum lysozyme level in chickens. Total non-additive components of variance also showed significant amount of heterosis in crossbred progenies, and therefore exploitation of non-additive component of variance is possible for improvement in serum lysozyme level in broilers. The overall results suggested that for commercial broiler production system, the selection for specialised line on the basis of serum lysozyme level and subsequent crossing of parent lines could enhance the immunocompetence status in relation to serum lysozyme level in crossbred chickens.