• Title/Summary/Keyword: singular matrix problem

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Development of Inverse Solver based on TSVD in Electrical Impedance Tomography (전기 임피던스 단층촬영법에서 TSVD 기반의 역문제 해법의 개발)

  • Kim, Bong Seok;Kim, Chang Il;Kim, Kyung Youn
    • Journal of the Institute of Electronics and Information Engineers
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    • v.54 no.4
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    • pp.91-98
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    • 2017
  • Electrical impedance tomography is a nondestructive imaging technique to reconstruct unknown conductivity distribution based on applied current data and measured voltage data through an array of electrodes attached on the periphery of a domain. In this paper, an inverse method based on truncated singular value decomposition is proposed to solve the inverse problem with the generalized Tikhonov regularization and to reconstruct the conductivity distribution. In order to reduce the inverse computational time, truncated singular value decomposition is applied to the inverse term after the generalized regularization matrix is taken out from the inverse matrix term. Numerical experiments and phantom experiments have been performed to verify the performance of the proposed method.

Design of a Recommendation System for Improving Deep Neural Network Performance

  • Juhyoung Sung;Kiwon Kwon;Byoungchul Song
    • Journal of Internet Computing and Services
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    • v.25 no.1
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    • pp.49-56
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    • 2024
  • There have been emerging many use-cases applying recommendation systems especially in online platform. Although the performance of recommendation systems is affected by a variety of factors, selecting appropriate features is difficult since most of recommendation systems have sparse data. Conventional matrix factorization (MF) method is a basic way to handle with problems in the recommendation systems. However, the MF based scheme cannot reflect non-linearity characteristics well. As deep learning technology has been attracted widely, a deep neural network (DNN) framework based collaborative filtering (CF) was introduced to complement the non-linearity issue. However, there is still a problem related to feature embedding for use as input to the DNN. In this paper, we propose an effective method using singular value decomposition (SVD) based feature embedding for improving the DNN performance of recommendation algorithms. We evaluate the performance of recommendation systems using MovieLens dataset and show the proposed scheme outperforms the existing methods. Moreover, we analyze the performance according to the number of latent features in the proposed algorithm. We expect that the proposed scheme can be applied to the generalized recommendation systems.

Observer-Based Output-feedback Sampled-Data Controlling the Singularly Perturbed Takagi-Sugeno Fuzzy Model (특이섭동 타카기 수게노 퍼지모델의 관측기기반 - 출력궤환 샘플치제어)

  • Kang, Hyoung Bin;Moon, Ji Hyun;Lee, Ho Jae
    • Journal of Institute of Control, Robotics and Systems
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    • v.22 no.9
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    • pp.679-685
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    • 2016
  • This paper addresses an observer-based output-feedback sampled-data controller design problem for nonlinear systems in Takagi-Sugeno (T-S) form including singular perturbations. The design condition is represented in terms of linear matrix inequalities. The separation principle is also investigated.

Vision Based Map-Building Using Singular Value Decomposition Method for a Mobile Robot in Uncertain Environment

  • Park, Kwang-Ho;Kim, Hyung-O;Kee, Chang-Doo;Na, Seung-Yu
    • 제어로봇시스템학회:학술대회논문집
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    • 2001.10a
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    • pp.101.1-101
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    • 2001
  • This paper describes a grid mapping for a vision based mobile robot in uncertain indoor environment. The map building is a prerequisite for navigation of a mobile robot and the problem of feature correspondence across two images is well known to be of crucial Importance for vision-based mapping We use a stereo matching algorithm obtained by singular value decomposition of an appropriate correspondence strength matrix. This new correspondence strength means a correlation weight for some local measurements to quantify similarity between features. The visual range data from the reconstructed disparity image form an occupancy grid representation. The occupancy map is a grid-based map in which each cell has some value indicating the probability at that location ...

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Mode-SVD-Based Maximum Likelihood Source Localization Using Subspace Approach

  • Park, Chee-Hyun;Hong, Kwang-Seok
    • ETRI Journal
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    • v.34 no.5
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    • pp.684-689
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    • 2012
  • A mode-singular-value-decomposition (SVD) maximum likelihood (ML) estimation procedure is proposed for the source localization problem under an additive measurement error model. In a practical situation, the noise variance is usually unknown. In this paper, we propose an algorithm that does not require the noise covariance matrix as a priori knowledge. In the proposed method, the weight is derived by the inverse of the noise magnitude square in the ML criterion. The performance of the proposed method outperforms that of the existing methods and approximates the Taylor-series ML and Cram$\acute{e}$r-Rao lower bound.

Robust Passive Low-order Filtering for Discrete-time Uncertain Descriptor Systems (이산시간 불확실 특이시스템의 저차 강인 피동성 필터링)

  • Kim, Jong-Hae;Oh, Do-Cang
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.61 no.3
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    • pp.466-471
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    • 2012
  • In this paper, we consider the problem of a robust passive filtering with low-order for discrete-time singular systems with polytopic uncertainties. A BRL(bounded real lemma) for robust passivity with a dissipativity of discrete-time uncertain singular systems is derived. A low-order robust passive filter design method is proposed by new reduced-order method and LMI(linear matrix inequality) technique on the basis of the obtained BRL. Finally, illustrative examples are presented to show the applicability of the proposed method.

Force Transmission Analyses with Dimensionally Homogeneous Jacobian Matrices for Parallel Manipulators

  • Kim, Sung-Gaun;Jeha Ryu
    • Journal of Mechanical Science and Technology
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    • v.18 no.5
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    • pp.780-788
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    • 2004
  • To avoid the unit inconsistency problem in the conventional Jacobian matrix, new formulation of a dimensionally homogeneous inverse Jacobian matrix for parallel manipulators with a planar mobile platform by using three end-effector points was presented (Kim and Ryu, 2003). This paper presents force relationships between joint forces and Cartesian forces at the three End-Effector points. The derived force relationships can then be used for analyses of the input/output force transmission. These analyses, forward and inverse force transmission analyses, depend on the singular values of the derived unit consistent Jacobian matrix. Using the proposed force relationship, a numerical example is presented for actuator size design of a 3-RRR planar parallel manipulator.

Inverse and Forward Force Transmission Analyses of Parallel Manipulators using Dimensionally Homogeneous Jacobian Matrices (유니트 일치된 자코비안 행렬을 이용한 병렬구조 로봇의 힘전달 해석)

  • Kim, Sung-Gaun;Ryu, Je-Ha
    • Proceedings of the KSME Conference
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    • 2003.11a
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    • pp.1500-1505
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    • 2003
  • In order to avoid the unit inconsistency problem in the conventional Jacobian matrix, previously we presented new formulation of a dimensionally homogeneous inverse Jacobian matrix for parallel manipulators with a planar mobile platform by using three end-effector points based on the velocity relationship [1]. This paper presents force relationships between joint forces and Cartesian forces at the three End-Effector points. The derived force relationships can then be used for analyses of the input/output force transmission. These analyses, forward and inverse force transmission analyses, depend on the singular values of the derived dimensionally homogeneous Jacobian matrix. Using the proposed force relationship, a numerical example is presented for actuator size design of a 3-RRR planar parallel manipulator.

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Robust Stabilization and Guaranteed Cost Control for Discrete-time Singular Systems with Parameter Uncertainties (변수 불확실성을 가지는 이산시간 특이시스템의 강인 안정화 및 강인 보장비용 제어)

  • Kim, Jong-Hae
    • Journal of the Institute of Electronics Engineers of Korea SC
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    • v.46 no.3
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    • pp.15-21
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    • 2009
  • In this paper, we consider the design problem of robust stabilization and robust guaranteed cost state feedback controller for discrete-time singular systems with parameter uncertainties by LMI(linear matrix inequality) approach without semi-definite condition and decomposition of system matrices. The objective of robust stabilization controller is to construct a state feedback controller such that the closed-loop system is regular, causal, and stable. In the case of robust guaranteed cost control, the optimal value of guaranteed cost and controller design method are presented on the basis of robust stabilization control technique. Finally, a numerical example is provided to show the validity of the design methods.

Compressed Sensing of Low-Rank Matrices: A Brief Survey on Efficient Algorithms (낮은 계수 행렬의 Compressed Sensing 복원 기법)

  • Lee, Ki-Ryung;Ye, Jong-Chul
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.46 no.5
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    • pp.15-24
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    • 2009
  • Compressed sensing addresses the recovery of a sparse vector from its few linear measurements. Recently, the success for the vector case has been extended to the matrix case. Compressed sensing of low-rank matrices solves the ill-posed inverse problem with fie low-rank prior. The problem can be formulated as either the rank minimization or the low-rank approximation. In this paper, we survey recently proposed efficient algorithms to solve these two formulations.