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  • Open Access


    New Three-Dimensional Assessment Model and Optimization of Acoustic Positioning System

    Lin Zhao1, Xiaobo Chen1, 2, *, Jianhua Cheng1, Lianhua Yu3, Chengcai Lv4, Jiuru Wang5

    CMC-Computers, Materials & Continua, Vol.64, No.2, pp. 1005-1023, 2020, DOI:10.32604/cmc.2020.010290

    Abstract This paper addresses the problem of assessing and optimizing the acoustic positioning system for underwater target localization with range measurement. We present a new three-dimensional assessment model to evaluate the optimal geometric beacon formation whether meets user requirements. For mathematical tractability, it is assumed that the measurements of the range between the target and beacons are corrupted with white Gaussian noise with variance, which is distance-dependent. Then, the relationship between DOP parameters and positioning accuracy can be derived by adopting dilution of precision (DOP) parameters in the assessment model. In addition, the optimal geometric beacon… More >

  • Open Access


    Inaccuracy of a continuous arterial pressure waveform monitor when used for congenital cardiac catheterization

    Michael D. Seckeler1, Katri Typpo2, Jendar Deschenes2, Ruth Higgins3, Ricardo Samson1, Peter Lichtenthal4

    Congenital Heart Disease, Vol.12, No.6, pp. 815-819, 2017, DOI:10.1111/chd.12517

    Abstract Objective: To determine the accuracy of a continuous cardiac output monitor (FloTrac sensor) for measuring cardiac index in children with congenital heart disease undergoing cardiac catheterization. Cardiac index is a critical hemodynamic parameter measured during catheterizations in children with congenital heart disease. This has been challenging to measure accurately and many clinicians rely on predictive equations for calculating cardiac index.
    Design: Prospective, nonrandomized trial.
    Setting: Tertiary care congenital heart center.
    Patients: Consecutive participants ≤18 years old undergoing clinically indicated cardiac catheterizations from September 2014 through August 2015.
    Interventions: Oxygen consumption was measured using the Vmax Encore 229 monitor attached to… More >

  • Open Access


    Identification of adults with congenital heart disease of moderate or great complexity from administrative data

    Jill M. Steiner1, James N. Kirkpatrick1, Susan R. Heckbert2, Asma Habib1, James Sibley3, William Lober3, J. Randall Curtis3

    Congenital Heart Disease, Vol.13, No.1, pp. 65-71, 2018, DOI:10.1111/chd.12524

    Abstract Introduction: There is relatively sparse literature on the use of administrative datasets for research in patients with adult congenital heart disease (ACHD). The goal of this analysis is to examine the accuracy of administrative data for identifying patients with ACHD who died.
    Methods: A list of the International Classification of Diseases codes representing ACHD of moderate- or great-complexity was created. A search for these codes in the electronic health record of adults who received care in 2010–2016 was performed, and used state death records to identify patients who died during this period. Manual record review was completed… More >

  • Open Access


    Accuracy of risk prediction scores in pregnant women with congenital heart disease

    Yuli Y. Kim1,2, Leah A. Goldberg2, Katherine Awh2, Tanmay Bhamare1,2, David Drajpuch2, Adi Hirshberg3, Sara L. Partington1,2, Rachel Rogers4, Emily Ruckdeschel1,2, Lynda Tobin1, Morgan Venuti2, Lisa D. Levine3

    Congenital Heart Disease, Vol.14, No.3, pp. 470-478, 2019, DOI:10.1111/chd.12750

    Abstract Objective: To assess performance of risk stratification schemes in predicting adverse cardiac outcomes in pregnant women with congenital heart disease (CHD) and to compare these schemes to clinical factors alone.
    Design: Single‐center retrospective study.
    Setting: Tertiary care academic hospital.
    Patients: Women ≥18 years with International Classification of Diseases, Ninth Revision, Clinical Modification codes indicating CHD who delivered between 1998 and 2014. CARPREG I and ZAHARA risk scores and modified World Health Organization (WHO) criteria were applied to each woman.
    Outcome Measures: The primary outcome was defined by ≥1 of the following: arrhyth‐ mia, heart failure/pulmonary edema, transient ischemic attack, stroke,… More >

  • Open Access


    Effects of Tangent Operators on Prediction Accuracy of Meso-mechanical Constitutive Model of Elasto-plastic Composites

    Sujuan Guo, Guozheng Kang, Juan Zhang

    The International Conference on Computational & Experimental Engineering and Sciences, Vol.18, No.4, pp. 121-122, 2011, DOI:10.3970/icces.2011.018.121

    Abstract With a newly developed homogenization cyclic constitutive model of particle reinforced metal matrix composites (Guo et al., 2011), the effects of tangent operators, i.e., continuum and algorithmic tangent operators [defined by Doghri and Ouaar (2003)] on the accuracy of the developed meso-mechanical constitutive model to predict the monotonic tensile and uniaxial ratchetting deformation of SiCP/6061Al composites were investigated in this work. The predicted results were obtained by the developed model with the choices of different tangent operators and various magnitudes of loading increments. Some useful accuracy comparison and error analysis on the predicted results were More >

  • Open Access


    Averaging TRIAD Algorithm for attitude determination

    Dong-Hoon Kim1, Sang-Wook Lee1, Dong-Ik Cheon1, Hwa-Suk Oh1

    The International Conference on Computational & Experimental Engineering and Sciences, Vol.11, No.2, pp. 33-34, 2009, DOI:10.3970/icces.2009.011.033

    Abstract In general, accurate attitude information is essential to perform the mission. Two algorithms are well-known to determine the attitude through two or more vector observations. One is deterministic method such as TRIAD algorithm, the other is optimal method such as QUEST algorithm. This paper suggests the idea to improve performance of the TRIAD algorithm and to determine the attitude by combination of different sensors. First, we change the attitude matrix to Euler angle instead of using orthogonalization method and also use covariance in place of variance, then apply an unbiased minimum variance formula for more More >

  • Open Access


    Patient Specific Knee Joint Finite Element Model Validation with High Accuracy Kinematics from Biplane Dynamic Radiography

    G. Papaioannou1, G. Nianios1, C. Mitroyiannis1, S.Tashman2, K.H. Yang2

    The International Conference on Computational & Experimental Engineering and Sciences, Vol.8, No.1, pp. 7-12, 2008, DOI:10.3970/icces.2008.008.007

    Abstract Little is known about in vivo menisci loads and displacements in the knee during strenuous activities. We have developed a method that combines biplane high-speed dynamic radiography (DRSA) and a subject-specific finite element model for studying in vivo meniscal behavior. In a very controlled uniaxial compression loading condition, removing of the pressure sensor from the model can result in relatively large errors in contact and cartilage stress that are not reflected in the change of meniscal displacement. More >

  • Open Access


    Influence of the Regression Error of the Response Surface to the Diagnostic Accuracy of the Unsupervised Statistical Damage Diagnostic Method

    A.Iwasaki1, K.Yuguchi2, A.Todoroki3, Y.Shimamura4

    The International Conference on Computational & Experimental Engineering and Sciences, Vol.6, No.3, pp. 183-188, 2008, DOI:10.3970/icces.2008.006.183

    Abstract The present study is about study on the diagnostic accuracy of the unsupervised damage diagnosis method named SI-F method. For the health monitoring of existing structures, modeling of entire structure or obtaining data sets after creating damage for training is almost impossible. This raises significant demand for development of a low-cost diagnostic method that does not require modeling of entire structure or data on damaged structure. Therefore, the present study proposes a low-cost unsupervised statistical diagnostic method for structural damage detection. The proposed method statistically diagnoses structural condition by means of investigating the change of… More >

  • Open Access


    Accuracy and Computational Efficiency of the Finite Volume Method Combined with the Meshless Local Petrov-Galerkin in Comparison with the Finite Element Method in Elasto-static Problem

    M.R. Moosavi1, A. Khelil1

    The International Conference on Computational & Experimental Engineering and Sciences, Vol.5, No.4, pp. 211-238, 2008, DOI:10.3970/icces.2008.005.211

    Abstract In this paper, a combined formulation of the Finite Volume Method (FVM) and the Meshless Local Petrov-Galerkin (MLPG) is investigated to solve elasto-static problem. Accuracy and computational efficiency study between the combined formulation and the Finite Element Method (FEM) is presented. Some problems of beam under various loading and boundary conditions are analyzed by the proposed method, and the numerical results are compared with analytical solution and result of other numerical method which is obtained by well-known FEM software ABAQUS. The advantages of the FVM combined MLPG (FVMLPG) with respect to the FEM are illustrated. More >

  • Open Access


    The Quality Assessment of Non-Integer-Hour Data in GPS Broadcast Ephemerides and Its Impact on the Accuracy of Real-Time Kinematic Positioning Over the South China Sea

    Zhangzhen Sun1, Tianhe Xu1,*, Fan Gao1, Chunhua Jiang1, Guochang Xu1

    CMES-Computer Modeling in Engineering & Sciences, Vol.119, No.2, pp. 263-280, 2019, DOI:10.32604/cmes.2019.04425

    Abstract Abnormal effects in GPS broadcast ephemerides can have a significant effect on real-time navigation and positioning solutions that use the orbit and clock error data provided by GPS broadcast ephemerides. This paper describes three types of non-integer-hour navigation data in GPS broadcast ephemeris data. Compared with GPST integer hour data, we find that there are two types of data blocks for non-integer-hour navigation containing gross errors with different levels of precision, which is reflected in the user range accuracy (URA) of the broadcast ephemeris. These gross errors can cause large deviations when using the GPS… More >

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