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measurement-errors
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Remedial measures to lessen the effect of imprecise measurement with linearly increasing variance on the performance of the MAX-EWMAMS scheme
, Article Arabian Journal for Science and Engineering ; Volume 43, Issue 6 , June , 2018 , Pages 3151-3162 ; 2193567X (ISSN) ; Maleki, M. R ; Akhavan Niaki, S. T ; Sharif University of Technology
Springer Verlag
2018
Abstract
Simultaneous monitoring of process mean and variability by a single control chart has been increasingly taken into consideration in recent years. However, the effect of imprecise measurements on the performances of some existing control schemes has been neglected. In this paper, the effect of measurement errors with linearly increasing variance on the detecting and diagnosing capability of the MAX-EWMAMS control chart is first investigated in Phase II monitoring. The results obtained using simulation studies show that the measurement errors affect the two performances of the chart, significantly. Then, two remedial measures including the ranked set sampling approach and using a larger sample...
Effects of linear acceleration in a harmonically excited proof mass MEMS rate gyroscope
, Article Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science ; Volume 232, Issue 19 , 2018 , Pages 3551-3563 ; 09544062 (ISSN) ; Salarieh, H ; Sharif University of Technology
SAGE Publications Ltd
2018
Abstract
MEMS rate gyroscopes are prone to different errors because of environmental conditions and manufacturing errors. These errors can result to mismatch between the fabricated gyros and the designed ones. Different environmental conditions and disturbances can change the parameters and specifications of a gyro, and its sensitivity may deteriorate, since the parameters are different from the optimal ones. External linear acceleration is one of the main environmental disturbances that may change the behavior of an MEMS rate gyro that its effect on the accuracy of an MEMS proof mass gyroscope is found here. This is done by finding the equations of motion of gyroscope in presence of acceleration and...
Single-replicate longitudinal data analysis in the presence of multiple instrumental measurement errors
, Article Computers and Industrial Engineering ; Volume 141 , 2020 ; Behbahani, M ; Khedmati, M ; Akhavan Niaki, S. T ; Sharif University of Technology
Elsevier Ltd
2020
Abstract
In this paper, a novel method as a combination of the expectation–maximization (EM) algorithm and Variogram is proposed to decompose the longitudinal measurement errors in the absence of replications and the presence of multiple instrumental measurement errors. In the proposed method, multiple measurements are considered where the units are observed by several distinct instruments (gauges). The approach decouples the observed variance of the measurement model into the process and measurement system variances. In addition, it decomposes the variance of multiple instruments into the process and instrument variances. In the end, the proposed model is validated and tested based on simulated...
An inverse problem method for overall heat transfer coefficient estimation in a partially filled rotating cylinder
, Article Heat Transfer Engineering ; Volume 29, Issue 3 , 2008 , Pages 272-283 ; 01457632 (ISSN) ; Heydari, M. M ; Sharif University of Technology
2008
Abstract
The objective of this article is to study the estimation of an overall heat transfer coefficient in a partially filled rotating cylinder. Herein is an inverse analysis for estimating the overall heat transfer coefficient in an arbitrary cross-section of the aforementioned system from the temperatures measured on the shell. The material employs the finite-volume method to solve the direct problem. The hybrid effective algorithm applied here contains the local optimization algorithm to estimate the unknown parameter by minimizing the objective function. The data measured here are simulated by adding random errors to the exact solution. An investigation is made of the impact of the measurement...
Investigation of error propagation and measurement error for 2D block method in Electrical Impedance Tomography
, Article 2015 2nd International Conference on Pattern Recognition and Image Analysis, IPRIA 2015, 11 March 2015 through 12 March 2015 ; 2015 ; 9781479984459 (ISBN) ; Amirfattahi, R ; Vosoughi Vahdat, B ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2015
Abstract
2D block method (2D BM) is a new approach to solve inverse problem as one of the most challenging case in Electrical Impedance Tomography (EIT). In this method, a tissue is modeled by some blocks to construct a medical image of a body limb. Recently, a non-iterative linear inverse solution is introduced to solve the inverse problem in the 2D BM. But effect of measurement error has not been considered for non-iterative linear inverse solution yet. In this paper, an appropriate method is proposed to investigate the error propagation in 2D BM. The effect of measurement error is considered as well through different examples. Results show that the BM is very sensitive to the measurement error and...
Error propagation in non-iterative EIT block method
, Article ISSPIT 2007 - 2007 IEEE International Symposium on Signal Processing and Information Technology, Cairo, 15 December 2007 through 18 December 2007 ; 2007 , Pages 678-681 ; 9781424418350 (ISBN) ; Pashakhanlou, F ; Vosoughi Vahdat, B ; Sharif University of Technology
2007
Abstract
The Block method approach to solve EIT problem leads to an exact solution if the measurements are done without error. Non-iterative method is a feasible approach on solving 3D EIT forward problem. However, the effect of the measurement error has not been considered in this method yet. In this article, the 3D model of EIT with block method has been considered. The required equations to solve the forward problem are then generated. To solve the forward problem, non-iterative method has been employed. Effect of the measurement error on forward problem for a 3D model of EIT are generated. It has been shown that for a sample 3D model, measurement error can propagate exponentially. ©2007 IEEE
Sensitivity analysis of configuration in bistatic radars
, Article 2nd Microwave and Radar Week in Poland - International Radar Symposium, IRS 2006, Krakow, 24 May 2006 through 26 May 2006 ; 2006 ; 8372076219 (ISBN); 9788372076212 (ISBN) ; Emadi, M ; Mousavi, M. R ; Jafargholi, A ; Nayebi, M. M ; Sharif University of Technology
2006
Abstract
There are inherent errors in target location and velocity measurement caused by bistatic geometry in addition to the errors that are caused in monostotic radars. In this paper, the accuracy of measurement with respect to some parameters like baseline variance and DOA estimation is considered and bistatic parameters sensitivity with respect together is formulated
Sagittal range of motion of the thoracic spine using inertial tracking device and effect of measurement errors on model predictions
, Article Journal of Biomechanics ; Volume 49, Issue 6 , 2016 , Pages 913-918 ; 00219290 (ISSN) ; Arjmand, N ; Sharif University of Technology
Elsevier Ltd
Abstract
Range of motion (ROM) of the thoracic spine has implications in patient discrimination for diagnostic purposes and in biomechanical models for predictions of spinal loads. Few previous studies have reported quite different thoracic ROMs. Total (T1-T12), lower (T5-T12) and upper (T1-T5) thoracic, lumbar (T12-S1), pelvis, and entire trunk (T1) ROMs were measured using an inertial tracking device as asymptomatic subjects flexed forward from their neutral upright position to full forward flexion. Correlations between body height and the ROMs were conducted. An effect of measurement errors of the trunk flexion (T1) on the model-predicted spinal loads was investigated. Mean of peak voluntary total...
Multijoint coordination during sit-to-stand task in people with non-specific chronic low back pain
, Article Biomedical Engineering - Applications, Basis and Communications ; Volume 25, Issue 1 , 2013 ; 10162372 (ISSN) ; Negahban, H ; Shaterzadeh, M. J ; Mehravar, M ; Salehi, R ; Narimani, R ; Parnianpour, M ; Sharif University of Technology
2013
Abstract
Sit-to-stand (STS) is an important functional task affected by low back pain (LBP). It requires fundamental coordination among all segments of the body to control important performance variables such as body's center of mass (CM) and head positions. This study was conducted to determine whether LBPs could coordinate their multiple joints to achieve the task stability to the same extent as healthy controls. About 11 non-specific chronic LBP and 12 healthy control subjects performed STS task at three postural difficulty levels: rigid surface - open eyes (RO), rigid surface - closed eyes (RC) and narrow surface - closed eyes (NC). Motion variability of seven body segments, CM and head positions...
Measurement, analysis and reconstruction of residual stresses
, Article Journal of Strain Analysis for Engineering Design ; Volume 47, Issue 4 , February , 2012 , Pages 254-264 ; 03093247 (ISSN) ; Goudar, D ; Farrahi, G. H ; Smith, D. J ; Sharif University of Technology
2012
Abstract
Residual stresses, created in a steel beam by elastic-plastic bending, are predicted using an approximate analysis and the finite element method. The predictions are compared to experimental measurements obtained from the application of incremental centre hole drilling, deep hole drilling and neutron diffraction methods. Finite element simulations of the incremental centre hole drilling and deep hole drilling methods applied to the predicted residual stresses permitted an assessment of their ability to reconstruct the stresses. An analytical reconstruction analysis using an Airy stress function together with boundary and equilibrium conditions is developed and applied to the predictions and...
Comprehensive study of non-uniform circular array interferometer in a real time broadband 3-dimensional direction finder (2-12GHZ)
, Article Progress In Electromagnetics Research C ; Volume 24 , 2011 , Pages 69-81 ; 19378718 (ISSN) ; Soltanian, M ; Salarpour, M ; Pezeshk, A. M ; Sharif University of Technology
2011
Abstract
A comprehensive study is performed to investigate the performance of a non-uniform circular array interferometer in a real time 3-dimensional direction finder. The angular range of view is supposed to be 65 degrees vertically and 120 degrees horizontally, which is suitable for airborne applications. Interferometer is designed to work in the S, C and X bands. Regarding optimization process, the interferometer employs an eight element non-uniform circular array along with a phase reference antenna at the center of the array. Several quantities and parameters are studied, e.g., frequency behavior, origins of phase measurement errors, Signal to Noise Ratio (SNR) effect on phase measurement, and...
Error concealment using wide motion vector space for H.264/AVC
, Article 2011 19th Iranian Conference on Electrical Engineering, ICEE 2011, 17 May 2011 through 19 May 2011 ; May , 2011 ; 9789644634284 (ISBN) ; Panahi, M. A ; Kasaei, S ; Sharif University of Technology
2011
Abstract
Due to fast growth of wireless mobile networks, video transmission over wireless media has been widely studied. As wireless networks are error prone, there is a high possibility of loss in sent packets. Since time limitations in real-time video applications should be met, the delay-related to resending packets is not acceptable and the error should to be concealed at receiver side. With respect to different concealment methods, two new methods for temporal error concealment are proposed. In the first method, an optimized set of motion vectors is formed using motion vectors in surrounding blocks of the lost macroblock, and then this set is searched for the best motion vector. For extending...
An adaptive pmu-based wide area backup protection scheme for power transmission lines
, Article IEEE Transactions on Smart Grid ; Volume 6, Issue 3 , January , 2015 , Pages 1550-1559 ; 19493053 (ISSN) ; Ranjbar, A. M ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2015
Abstract
This paper proposes a novel adaptive wide area backup protection scheme for transmission lines. In the proposed scheme, both the faulted line and fault location are determined by a limited number of synchronized phasor measurements. Based on phasor measurement unit placement and network topology, subsets of lines and buses called backup protection zones (BPZs) are formed. After a fault occurs in the transmission network, the sum of zero- and/or positive-sequence currents entering the faulted BPZ highly increases, and hence, the faulted BPZ can be determined. The linear least squares method is then used to determine the faulted line, as well as the fault location by voltage and current...
A novel method for fault location of transmission lines by wide-area voltage measurements considering measurement errors
, Article IEEE Transactions on Smart Grid ; Volume 6, Issue 2 , 2015 , Pages 874-884 ; 19493053 (ISSN) ; Ranjbar, A. M ; Sharif University of Technology
Abstract
Smart transmission grids are intended to utilize various measurements for enhanced operation. In particular, synchronized phasor measurements have found many applications in this context. This paper presents a linear weighted least-squares (WLS) method for fault location estimation of transmission lines by synchronized voltage measurements. The measurements may be taken from the faulted line terminals or buses far from the faulted line. The circuit equations of the network are used to find the transfer function between the fault location and each voltage measurement. Next, two auxiliary variables are defined to transform the nonlinear fault location estimation problem into a linear WLS...
A comprehensive multimodality heart motion prediction algorithm for robotic-assisted beating heart surgery
, Article International Journal of Medical Robotics and Computer Assisted Surgery ; Volume 15, Issue 2 , 2019 ; 14785951 (ISSN) ; Farahmand, F ; Vossoughi, G ; Alizadeh Ghavidel, A ; Sharif University of Technology
John Wiley and Sons Ltd
2019
Abstract
Background: An essential requirement for performing robotic-assisted surgery on a freely beating heart is a prediction algorithm that can estimate the future heart trajectory. Method: Heart motion, respiratory volume (RV) and electrocardiogram (ECG) signal were measured from two dogs during thoracotomy surgery. A comprehensive multimodality prediction algorithm was developed based on the multivariate autoregressive model to incorporate the heart trajectory and cardiorespiratory data with multiple inherent measurement rates explicitly. Results: Experimental results indicated strong relationships between the dominant frequencies of heart motion with RV and ECG. The prediction algorithm...
An inverse problem method for gas temperature estimation in partially filled rotating cylinders
, Article Scientia Iranica ; Volume 15, Issue 5 , 2008 , Pages 584-595 ; 10263098 (ISSN) ; Farhanieh, B ; Sharif University of Technology
Sharif University of Technology
2008
Abstract
The objective of this article is to study gas temperature estimation in a partially filled rotating cylinder. From the measured temperatures on the shell, an inverse analysis is presented for estimating the gas temperature in an arbitrary cross-section of the aforementioned system. A finite-volume method is employed to solve the direct problem. By minimizing the objective function, a hybrid effective algorithm, which contains a local optimization algorithm, is adopted to estimate the unknown parameter. The measured data are simulated by adding random errors to the exact solution. The effects of measurement errors on the accuracy of the inverse analysis are investigated. Two optimization...
Dual criterion equivalent linearization approach for yielding structures under earthquake excitation
, Article Structural Design of Tall and Special Buildings ; Volume 21, Issue 3 , 2012 , Pages 155-177 ; 15417794 (ISSN) ; Khaloo, A ; Sharif University of Technology
Abstract
In order to estimate both maximum displacement and maximum inertia force of bilinear hysteretic system subjected to earthquake motions, an equivalent linearization approach with new effective parameters is presented. Effective mass and effective damping ratio as pair of effective parameters instead of the effective period and effective damping ratio in existing equivalent linear systems are introduced. Two error measures for displacement and inertia force are defined. Error distributions over a two-dimensional parameter space of effective parameters are analysed, and the parameters are determined through a statistical approach with a dual optimization criterion for displacement and inertia...
Effects of higher oscillation modes on TM-AFM measurements
, Article Ultramicroscopy ; Volume 111, Issue 2 , 2011 , Pages 107-116 ; 03043991 (ISSN) ; Meghdari, A ; Sharif University of Technology
Abstract
The finite element method and molecular dynamics simulations are used for modeling the AFM microcantilever dynamics and the tip-sample interaction forces, respectively. Molecular dynamics simulations are conducted to calculate the tip-sample force data as a function of tip height at different lateral positions of the tip with respect to the sample. The results demonstrate that in the presence of nonlinear interaction forces, higher eigenmodes of the microcantilever are excited and play a significant role in the tip and sample elastic deformations. Using comparisons between the results of FEM and lumped models, how some aspects of the system behavior can be hidden when the point-mass model is...
Identification of catecholamine neurotransmitters using fluorescence sensor array
, Article Analytica Chimica Acta ; Volume 917 , 2016 , Pages 85-92 ; 00032670 (ISSN) ; Hormozi Nezhad, M. R ; Mahmoudi, M ; Sharif University of Technology
Elsevier B.V
2016
Abstract
A nano-based sensor array has been developed for identification and discrimination of catecholamine neurotransmitters based on optical properties of their oxidation products under alkaline conditions. To produce distinct fluorescence response patterns for individual catecholamine, quenching of thioglycolic acid functionalized cadmium telluride (CdTe) quantum dots, by oxidation products, were employed along with the variation of fluorescence spectra of oxidation products. The spectral changes were analyzed with hierarchical cluster analysis (HCA) and principal component analysis (PCA) to identify catecholamine patterns. The proposed sensor could efficiently discriminate the individual...
Modification of DFIG's active power control loop for speed control enhancement and inertial frequency response
, Article IEEE Transactions on Sustainable Energy ; Volume 8, Issue 4 , 2017 , Pages 1772-1782 ; 19493029 (ISSN) ; Toulabi, M ; Bahrami, S ; Ranjbar, A. M ; Sharif University of Technology
Abstract
This paper proposes a fuzzy-based speed controller for the doubly fed induction generator (DFIG)-based wind turbines with the rotor speed and wind speed inputs. The controller parameters are optimized using the particle swarm optimization algorithm. To accelerate tracking the maximum power point trajectory, the conventional controller is augmented with a feed-forward compensator, which uses the wind speed input and includes a high-pass filter. The proposed combined speed controller is robust against wind measurement errors and as the accuracy of anemometers increases the speed regulation tends toward the ideal controller. The cutoff frequency of the applied filter is determined considering a...