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multivariant-analysis
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A novel analysis of critical water pollution in the transboundary Aras River using the Sentinel-2 satellite images and ANNs
, Article International Journal of Environmental Science and Technology ; Volume 19, Issue 9 , 2022 , Pages 9011-9026 ; 17351472 (ISSN) ; Zarghami, M ; Mosaferi, M ; Karimzadeh, S ; Sharif University of Technology
Springer Science and Business Media Deutschland GmbH
2022
Abstract
Recently, remote sensing considered as important tool in studies of water quality issues. The Aras River flows across a transboundary basin in northern Iran. In this study, the aim is to model the water quality parameters (WQPs) using remote sensing and an artificial neural network (ANN), which is a new method proposed to find WQPs based on multivariate regression approaches. The relationship between WQPs and digital data from the Sentinel-2 satellite was determined to estimate and map the WQPs in this river. Using the field data and digital image data, the obtained results show that multivariate regression approaches and high-resolution remote sensing could monitor and predict the...
A comprehensive evaluation of spine kinematics, kinetics, and trunk muscle activities during fatigue-induced repetitive lifting
, Article Human Factors ; Volume 64, Issue 6 , 2022 , Pages 997-1012 ; 00187208 (ISSN) ; Mazloumi, A ; Arjmand, N ; Keihani, A ; Karimi, Z ; Ghasemi, M. S ; Kordi, R ; Sharif University of Technology
SAGE Publications Inc
2022
Abstract
Objective: Spine kinematics, kinetics, and trunk muscle activities were evaluated during different stages of a fatigue-induced symmetric lifting task over time. Background: Due to neuromuscular adaptations, postural behaviors of workers during lifting tasks are affected by fatigue. Comprehensive aspects of these adaptations remain to be investigated. Method: Eighteen volunteers repeatedly lifted a box until perceived exhaustion. Body center of mass (CoM), trunk and box kinematics, and feet center of pressure (CoP) were estimated by a motion capture system and force-plate. Electromyographic (EMG) signals of trunk/abdominal muscles were assessed using linear and nonlinear approaches. The L5-S1...
Mutual information map as a new way for exploring the independence of chemically meaningful solutions in two-component analytical data
, Article Analytica Chimica Acta ; Volume 1227 , 2022 ; 00032670 (ISSN) ; Abdollahi, H ; Tauler, R ; Rukebusch, C ; Parastar, H ; Sharif University of Technology
Elsevier B.V
2022
Abstract
In the present contribution, a new approach based on mutual information (MI) is proposed for exploring the independence of feasible solutions in two component systems. Investigating how independent are different feasible solutions can be a way to bridge the gap between independent component analysis (ICA) and multivariate curve resolution (MCR) approaches and, to the best of our knowledge, has not been investigated before. For this purpose, different chromatographic and hyperspectral imaging (HSI) datasets were simulated, considering different noise levels and different degrees of overlap for two-component systems. Feasible solutions were then calculated by both grid search (GS) and...
Evaluation of FT-IR spectroscopy combined with SIMCA and PLS‑DA for detection of adulterants in pistachio butter
, Article Infrared Physics and Technology ; Volume 127 , 2022 ; 13504495 (ISSN) ; Bagheri Garmarudi, A ; Parastar, H ; Toth, G ; Sharif University of Technology
Elsevier B.V
2022
Abstract
This work scrutinized the adulteration of pistachio butter with three potential edible oils using Fourier transform infrared spectroscopy (FT-IR) and multivariate classification methods. Each of the classes, including non-adulterated samples and adulterated samples consisting of pistachio butter mixed with various concentrations of peanut oil, corn oil and sunflower oil, were classified. For this purpose, multivariate methods, including soft independent modeling of class analogy (SIMCA) and partial least squares discriminant analysis (PLS-DA), were applied to classify the FTIR data. After evaluating the model on unknown samples, the results indicated that PLS-DA was better than the SIMCA...
Circular economy adoption barriers: An extended fuzzy best–worst method using fuzzy DEMATEL and Supermatrix structure
, Article Business Strategy and the Environment ; Volume 31, Issue 4 , 2022 , Pages 1566-1586 ; 09644733 (ISSN) ; Khalili Nasr, A ; Karimi, F ; Mina, H ; Sharif University of Technology
John Wiley and Sons Ltd
2022
Abstract
In the real world, there are complex decision-making problems in which a variety of intertwined factors and hierarchical structures exist, and it is difficult or impossible to solve these problems using classical methods. The prioritization of circular economy (CE) adoption barriers is one such complex problem that cannot be solved using current classical methods. Hence, in this paper, for the first time, a new method, namely, FBWDS, is developed. FBWDS derives from the combination of fuzzy best–worst method (BWM), fuzzy decision-making trial and evaluation laboratory (DEMATEL), and Supermatrix structure. This proposed method establishes weights of the intertwined factors in hierarchical...
Recent trends in application of chemometric methods for GC-MS and GC×GC-MS-based metabolomic studies
, Article TrAC - Trends in Analytical Chemistry ; Volume 138 , 2021 ; 01659936 (ISSN) ; Hashemi Nasab, F. S ; Golpelichi, F ; Sabouruh, N ; Parastar, H ; Sharif University of Technology
Elsevier B.V
2021
Abstract
Metabolomics is the science of studying small molecules (metabolites) in biological systems with the aim of getting insight into cells, biofluids and organisms. Chemometric methods are powerful tools to address data problems generated in metabolomic studies and to extract valuable information. This review focuses mainly on a range of chemometric methods used for processing of metabolomics data generated from gas chromatography-mass spectrometry (GC-MS) and comprehensive two-dimensional gas chromatography-mass spectrometry (GC × GC-MS). Herein, essential skills used for preprocessing of raw data, multivariate resolution, pattern recognition, variable selection and identification of...
Simultaneous detection and identification of thiometon, phosalone, and prothioconazole pesticides using a nanoplasmonic sensor array
, Article Food and Chemical Toxicology ; Volume 151 , 2021 ; 02786915 (ISSN) ; Abbasi Moayed, S ; Ghasemi, F ; Mahdavi, V ; Hormozi Nezhad, M. R ; Sharif University of Technology
Elsevier Ltd
2021
Abstract
In this work, a colorimetric sensor array has been designed for the identification and discrimination of thiometon (TM) and phosalone (PS) as organophosphate pesticides and prothioconazole (PC) as a triazole pesticide. For this purpose, two different plasmonic nanoparticles including unmodified gold nanoparticles (AuNPs) and unmodified silver nanoparticles (AgNPs) were used as sensing elements. The principle of the proposed strategy relied on the aggregation AuNPs and AgNPs through the cross-reactive interaction between the target pesticides and plasmonic nanoparticles. Therefore, these aggregation-induced UV–Vis spectra changes were utilized to discriminate the target pesticides with the...
Radial basis function-artificial neural network (RBF-ANN) for simultaneous fluorescent determination of cysteine enantiomers in mixtures
, Article Spectrochimica Acta - Part A: Molecular and Biomolecular Spectroscopy ; Volume 261 , 2021 ; 13861425 (ISSN) ; Reza Hormozi Nezhad, M ; Abdollahi, H ; Sharif University of Technology
Elsevier B.V
2021
Abstract
The determination of chiral compounds is critically important in chemical and pharmaceutical sciences. Cysteine amino acid is one of the important chiral compounds where each enantiomer (L and D) has different effects on fundamental physiological processes. The unique optical properties of nanoparticles make them a suitable probe for the determination of different analytes. In this work, the water-soluble thioglycolic acid (TGA)-capped cadmium-telluride (CdTe) quantum dots (QDs) were applied as optical nanoprobe for the simultaneous determination of cysteine enantiomers. The difference in the kinetics of the interactions between L- and D-cysteine with CdTe QDs is used for multivariate...
Using distance on the Riemannian manifold to compare representations in brain and in models
, Article NeuroImage ; Volume 239 , 2021 ; 10538119 (ISSN) ; Shirali, A ; Aghajan, H ; Nili, H ; Sharif University of Technology
Academic Press Inc
2021
Abstract
Representational similarity analysis (RSA) summarizes activity patterns for a set of experimental conditions into a matrix composed of pairwise comparisons between activity patterns. Two examples of such matrices are the condition-by-condition inner product and correlation matrix. These representational matrices reside on the manifold of positive semidefinite matrices, called the Riemannian manifold. We hypothesize that representational similarities would be more accurately quantified by considering the underlying manifold of the representational matrices. Thus, we introduce the distance on the Riemannian manifold as a metric for comparing representations. Analyzing simulated and real fMRI...
Phase II monitoring of generalized linear profiles under different types of changes
, Article Scientia Iranica ; Volume 28, Issue 1 E , 2021 , Pages 557-571 ; 10263098 (ISSN) ; Mahlooji, H ; Sharif University of Technology
Sharif University of Technology
2021
Abstract
Various control charts have been proposed to monitor generalized linear pro les in Phase II. However, the robustness of the proposed methods in detecting di erent types and especially di erent directions of changes is not well-studied in the literature. In real-world applications, di erent kinds of change such as drift and multiple changes are likely to occur, which can be isotonic (increasing) or antitonic (decreasing). This paper studies the robustness of the Rao Score Test (RST) method, T2, and Multivariate Exponential Weighted Moving Average (MEWMA) in di erent types, drift and multiple, and directions of changes. The RST method also bene ts from a change-point detection approach whose...
Combining multivariate image analysis with high-performance thin-layer chromatography for development of a reliable tool for saffron authentication and adulteration detection
, Article Journal of Chromatography A ; Volume 1628 , 2020 ; Rashidi, M ; Kamyar, M ; Amirahmadi, M ; Daraei, B ; Parastar, H ; Sharif University of Technology
Elsevier B.V
2020
Abstract
In this work, high-performance thin-layer chromatography (HPTLC) coupled with multivariate image analysis (MIA) is proposed as a fast and reliable tool for authentication and adulteration detection of Iranian saffron samples based on their HPTLC fingerprints. At first, the secondary metabolites of saffron were extracted using ultrasonic-assisted solvent extraction (UASE) which was optimized using central composite design (CCD). Next, the RGB coordinates of HPTLC images were used for estimation of saffron origin based on principal component analysis (PCA). The PCA scores plot showed that saffron samples were clustered into two clear-cut groups which was 92% matched with the geographical...
Metabolic profiling of seminal plasma from teratozoospermia patients
, Article Journal of Pharmaceutical and Biomedical Analysis ; Volume 178 , January , 2020 ; Chashmniam, S ; Nobakht, F ; Amini, M ; Javidi, A ; Minai Tehrani, A ; Arjmand, B ; Gilany, K ; Sharif University of Technology
Elsevier B. V
2020
Abstract
Teratozoospermia is one of conditions that can cause male infertility. The mechanism of teratozoospermia remains unclear. The knowledge of the metabolites in human seminal plasma (HSP) is meaningful for the pathological study of teratozoospermia. Analysis of changed metabolites in HSP can help understand the cellular mechanism, find the novel biomarkers and subsequently design a diagnosis test. In this study, the analysis of samples performed by proton nuclear magnetic resonance spectroscopy (1H NMR spectroscopy) to identify the various metabolites, with the aim of finding metabolic profiles and biomarkers related to male infertility. Eighteen de-regulated metabolites were identified in...
Mode decomposition approach in robust control design for horizontal axis wind turbines
, Article Wind Energy ; Volume 23, Issue 2 , 2020 , Pages 312-326 ; Nobakhti, A ; Sharif University of Technology
John Wiley and Sons Ltd
2020
Abstract
A robust multivariable strategy for pitch and torque control design of variable-speed variable-pitch wind turbines in the full load region is introduced in this paper. The pitch and torque control loops that share the tracking and active damping of drivetrain torsional mode objectives are designed simultaneously using a novel decomposition scheme. This permits the systematic design of robust multivariable controllers for wind turbines in a manner that facilitates industrial application. We achieve this by making the process of weighting function design fast, intuitive, and simple and by giving the designer a clear insight on the compromising aspects of the various control system objectives....
Gas chromatographic fingerprint analysis of secondary metabolites of Stachys lanata (Stachys byzantine C. Koch) combined with antioxidant activity modelling using multivariate chemometric methods
, Article Journal of Chromatography A ; Volume 1602 , 2019 , Pages 432-440 ; 00219673 (ISSN) ; Abtahi, M ; Parastar, H ; Sharif University of Technology
Elsevier B.V
2019
Abstract
S. lanata has been traditionally used as a medicinal plant due to its various biological activities such as antioxidant activity. Therefore, identification and quality control studies of this plant are of great importance. To this end, gas chromatography (GC) combined with chemometrics was proposed for fingerprint analysis of S. lanata samples. This study sought to classify GC fingerprints of twenty-eight S. lanata samples from eight different regions of Iran and more importantly, to correlate fingerprints to the antioxidant activity to select S. lanata volatile antioxidant markers. S. lanata samples were classified into five and three classes using partial least squares-discriminant...
Chemometrics comparison of gas chromatography with mass spectrometry and comprehensive two-dimensional gas chromatography with time-of-flight mass spectrometry Daphnia magna metabolic profiles exposed to salinity
, Article Journal of Separation Science ; Volume 41, Issue 11 , 2018 , Pages 2368-2379 ; 16159306 (ISSN) ; Garreta Lara, E ; Campos, B ; Barata, C ; Lacorte, S ; Tauler, R ; Sharif University of Technology
Wiley-VCH Verlag
2018
Abstract
The performances of gas chromatography with mass spectrometry and of comprehensive two-dimensional gas chromatography with time-of-flight mass spectrometry are examined through the comparison of Daphnia magna metabolic profiles. Gas chromatography with mass spectrometry and comprehensive two-dimensional gas chromatography with mass spectrometry were used to compare the concentration changes of metabolites under saline conditions. In this regard, a chemometric strategy based on wavelet compression and multivariate curve resolution–alternating least squares is used to compare the performances of gas chromatography with mass spectrometry and comprehensive two-dimensional gas chromatography with...
Metabolomics diagnostic approach to mustard airway diseases: A preliminary study
, Article Iranian Journal of Basic Medical Sciences ; Volume 21, Issue 1 , 2018 , Pages 59-69 ; 20083866 (ISSN) ; Aliannejad, R ; Oskouie, A. A ; Tavirani, M. R ; Kalantari, S ; Naseri, M. T ; Baghban, A. A ; Parastar, H ; Aliakbarzadeh, G ; Sharif University of Technology
Mashhad University of Medical Sciences
2018
Abstract
Objective(s): This study aims to evaluate combined proton nuclear magnetic resonance (1H NMR) spectroscopy and gas chromatography-mass spectrometry (GC-MS) metabolic profiling approaches, for discriminating between mustard airway diseases (MADs) and healthy controls and for providing biochemical information on this disease. Materials and Methods: In the present study, analysis of serum samples collected from 17 MAD subjects and 12 healthy controls was performed using NMR. Of these subjects, 14 (8 patients and 6 controls) were analyzed by GC-MS. Then, their spectral profiles were subjected to principal component analysis (PCA) and orthogonal partial least squares regression discriminant...
Pattern recognition analysis of chromatographic fingerprints of Crocus sativus L. secondary metabolites towards source identification and quality control
, Article Analytical and Bioanalytical Chemistry ; Volume 408, Issue 12 , 2016 , Pages 3295-3307 ; 16182642 (ISSN) ; Sereshti, H ; Parastar, H ; Sharif University of Technology
Springer Verlag
2016
Abstract
Chromatographic fingerprinting is an effective methodology for authentication and quality control of herbal products. In the presented study, a chemometric strategy based on multivariate curve resolution-alternating least squares (MCR-ALS) and multivariate pattern recognition methods was used to establish a gas chromatography-mass spectrometry (GC-MS) fingerprint of saffron. For this purpose, the volatile metabolites of 17 Iranian saffron samples, collected from different geographical regions, were determined using the combined method of ultrasound-assisted solvent extraction (UASE) and dispersive liquid-liquid microextraction (DLLME), coupled with GC-MS. The resolved elution profiles and...
Chemometric-based determination of polycyclic aromatic hydrocarbons in aqueous samples using ultrasound-assisted emulsification microextraction combined to gas chromatography-mass spectrometry
, Article Journal of Chromatography A ; Volume 1413 , September , 2015 , Pages 117-126 ; 00219673 (ISSN) ; Sereshti, H ; Parastar, H ; Sharif University of Technology
Elsevier
2015
Abstract
In the present research, ultrasonic-assisted emulsification-microextraction (USAEME) coupled with gas chromatography-mass spectrometry (GC-MS) has been proposed for analysis of thirteen environmental protection agency (EPA) polycyclic aromatic hydrocarbons (PAHs) in aqueous samples. Tetrachloroethylene was selected as extraction solvent. The main parameters of USAEME affecting the efficiency of the method were modeled and optimized using a central composite design (CCD). Under the optimum conditions (9 μL for extraction solvent, 1.15% (w/v) NaCl (salt concentration) and 10min for ultrasonication time), preconcentration factor (PF) of the PAHs was in the range of 500-950. In order to have a...
A heuristic threshold policy for fault detection and diagnosis in multivariate statistical quality control environments
, Article International Journal of Advanced Manufacturing Technology ; Volume 67, Issue 5-8 , July , 2013 , Pages 1231-1243 ; 02683768 (ISSN) ; Niaki, S. T. A ; Sharif University of Technology
2013
Abstract
In this paper, a heuristic threshold policy is developed to detect and classify the states of a multivariate quality control system. In this approach, a probability measure called belief is first assigned to the quality characteristics and then the posterior belief of out-of-control characteristics is updated by taking new observations and using a Bayesian rule. If the posterior belief is more than a decision threshold, called minimum acceptable belief determined using a heuristic threshold policy, then the corresponding quality characteristic is classified out-of-control. Besides using a different approach, the main difference between the current research and previous works is that the...
A Max-EWMA approach to monitor and diagnose faults of multivariate quality control processes
, Article International Journal of Advanced Manufacturing Technology ; Volume 68, Issue 9-12 , 2013 , Pages 2283-2294 ; 02683768 (ISSN) ; Niaki, S. T. A ; Sharif University of Technology
2013
Abstract
A new approach is developed in this paper to detect general mean shifts of multivariate quality control systems and to determine the quality characteristic(s) responsible for the shift. This approach takes advantage of both a decomposition method and an EWMA-based control statistics that are employed for multivariate normal distributions. In order to evaluate the performance of the proposed methodology, simulation studies are provided to estimate the in- and out-of-control average run lengths under different mean and variance shift scenarios. Simulation experiments are also given to compare the performances of the proposed procedure with the ones of the well-known MEWMA and MCUSUM methods....