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  1. Book ; Online: Neural Networks with Kernel-Weighted Corrective Residuals for Solving Partial Differential Equations

    Mora, Carlos / Yousefpour, Amin / Hosseinmardi, Shirin / Bostanabad, Ramin

    2024  

    Abstract: Physics-informed machine learning (PIML) has emerged as a promising alternative to conventional numerical methods for solving partial differential equations (PDEs). PIML models are increasingly built via deep neural networks (NNs) whose architecture and ... ...

    Abstract Physics-informed machine learning (PIML) has emerged as a promising alternative to conventional numerical methods for solving partial differential equations (PDEs). PIML models are increasingly built via deep neural networks (NNs) whose architecture and training process are designed such that the network satisfies the PDE system. While such PIML models have substantially advanced over the past few years, their performance is still very sensitive to the NN's architecture and loss function. Motivated by this limitation, we introduce kernel-weighted Corrective Residuals (CoRes) to integrate the strengths of kernel methods and deep NNs for solving nonlinear PDE systems. To achieve this integration, we design a modular and robust framework which consistently outperforms competing methods in solving a broad range of benchmark problems. This performance improvement has a theoretical justification and is particularly attractive since we simplify the training process while negligibly increasing the inference costs. Additionally, our studies on solving multiple PDEs indicate that kernel-weighted CoRes considerably decrease the sensitivity of NNs to factors such as random initialization, architecture type, and choice of optimizer. We believe our findings have the potential to spark a renewed interest in leveraging kernel methods for solving PDEs.
    Keywords Computer Science - Machine Learning ; Mathematics - Numerical Analysis
    Subject code 518
    Publishing date 2024-01-07
    Publishing country us
    Document type Book ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  2. Article ; Online: Automatic classification of acute lymphoblastic leukemia cells and lymphocyte subtypes based on a novel convolutional neural network.

    MoradiAmin, Morteza / Yousefpour, Mitra / Samadzadehaghdam, Nasser / Ghahari, Laya / Ghorbani, Mahdi / Mafi, Majid

    Microscopy research and technique

    2024  

    Abstract: Acute lymphoblastic leukemia (ALL) is a life-threatening disease that commonly affects children and is classified into three subtypes: L1, L2, and L3. Traditionally, ALL is diagnosed through morphological analysis, involving the examination of blood and ... ...

    Abstract Acute lymphoblastic leukemia (ALL) is a life-threatening disease that commonly affects children and is classified into three subtypes: L1, L2, and L3. Traditionally, ALL is diagnosed through morphological analysis, involving the examination of blood and bone marrow smears by pathologists. However, this manual process is time-consuming, laborious, and prone to errors. Moreover, the significant morphological similarity between ALL and various lymphocyte subtypes, such as normal, atypic, and reactive lymphocytes, further complicates the feature extraction and detection process. The aim of this study is to develop an accurate and efficient automatic system to distinguish ALL cells from these similar lymphocyte subtypes without the need for direct feature extraction. First, the contrast of microscopic images is enhanced using histogram equalization, which improves the visibility of important features. Next, a fuzzy C-means clustering algorithm is employed to segment cell nuclei, as they play a crucial role in ALL diagnosis. Finally, a novel convolutional neural network (CNN) with three convolutional layers is utilized to classify the segmented nuclei into six distinct classes. The CNN is trained on a labeled dataset, allowing it to learn the distinguishing features of each class. To evaluate the performance of the proposed model, quantitative metrics are employed, and a comparison is made with three well-known deep networks: VGG-16, DenseNet, and Xception. The results demonstrate that the proposed model outperforms these networks, achieving an approximate accuracy of 97%. Moreover, the model's performance surpasses that of other studies focused on 6-class classification in the context of ALL diagnosis. RESEARCH HIGHLIGHTS: Deep neural networks eliminate the requirement for feature extraction in ALL classification The proposed convolutional neural network achieves an impressive accuracy of approximately 97% in classifying six ALL and lymphocyte subtypes.
    Language English
    Publishing date 2024-03-06
    Publishing country United States
    Document type Journal Article
    ZDB-ID 1099714-3
    ISSN 1097-0029 ; 1059-910X
    ISSN (online) 1097-0029
    ISSN 1059-910X
    DOI 10.1002/jemt.24551
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  3. Article ; Online: Laguerre Wavelet Approach for a Two-Dimensional Time-Space Fractional Schrödinger Equation.

    Bekiros, Stelios / Soradi-Zeid, Samaneh / Mou, Jun / Yousefpour, Amin / Zambrano-Serrano, Ernesto / Jahanshahi, Hadi

    Entropy (Basel, Switzerland)

    2022  Volume 24, Issue 8

    Abstract: This article is devoted to the determination of numerical solutions for the two-dimensional time-spacefractional Schrödinger equation. To do this, the unknown parameters are obtained using the Laguerre wavelet approach. We discretize the problem by using ...

    Abstract This article is devoted to the determination of numerical solutions for the two-dimensional time-spacefractional Schrödinger equation. To do this, the unknown parameters are obtained using the Laguerre wavelet approach. We discretize the problem by using this technique. Then, we solve the discretized nonlinear problem by means of a collocation method. The method was proven to give very accurate results. The given numerical examples support this claim.
    Language English
    Publishing date 2022-08-11
    Publishing country Switzerland
    Document type Journal Article
    ZDB-ID 2014734-X
    ISSN 1099-4300 ; 1099-4300
    ISSN (online) 1099-4300
    ISSN 1099-4300
    DOI 10.3390/e24081105
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  4. Book ; Online: Unsupervised Anomaly Detection via Nonlinear Manifold Learning

    Yousefpour, Amin / Shishehbor, Mehdi / Foumani, Zahra Zanjani / Bostanabad, Ramin

    2023  

    Abstract: Anomalies are samples that significantly deviate from the rest of the data and their detection plays a major role in building machine learning models that can be reliably used in applications such as data-driven design and novelty detection. The majority ...

    Abstract Anomalies are samples that significantly deviate from the rest of the data and their detection plays a major role in building machine learning models that can be reliably used in applications such as data-driven design and novelty detection. The majority of existing anomaly detection methods either are exclusively developed for (semi) supervised settings, or provide poor performance in unsupervised applications where there is no training data with labeled anomalous samples. To bridge this research gap, we introduce a robust, efficient, and interpretable methodology based on nonlinear manifold learning to detect anomalies in unsupervised settings. The essence of our approach is to learn a low-dimensional and interpretable latent representation (aka manifold) for all the data points such that normal samples are automatically clustered together and hence can be easily and robustly identified. We learn this low-dimensional manifold by designing a learning algorithm that leverages either a latent map Gaussian process (LMGP) or a deep autoencoder (AE). Our LMGP-based approach, in particular, provides a probabilistic perspective on the learning task and is ideal for high-dimensional applications with scarce data. We demonstrate the superior performance of our approach over existing technologies via multiple analytic examples and real-world datasets.
    Keywords Statistics - Machine Learning ; Computer Science - Machine Learning
    Subject code 006
    Publishing date 2023-06-15
    Publishing country us
    Document type Book ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  5. Article: Optimal policies for control of the novel coronavirus disease (COVID-19) outbreak.

    Yousefpour, Amin / Jahanshahi, Hadi / Bekiros, Stelios

    Chaos, solitons, and fractals

    2020  Volume 136, Page(s) 109883

    Abstract: Understanding the early transmission dynamics of diseases and estimating the effectiveness of control policies play inevitable roles in the prevention of epidemic diseases. To this end, this paper is concerned with the design of optimal control ... ...

    Abstract Understanding the early transmission dynamics of diseases and estimating the effectiveness of control policies play inevitable roles in the prevention of epidemic diseases. To this end, this paper is concerned with the design of optimal control strategies for the novel coronavirus disease (COVID-19). A mathematical model of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) transmission based on Wuhan's data is considered. To solve the problem effectively and efficiently, a multi-objective genetic algorithm is proposed to achieve high-quality schedules for various factors including contact rate and transition rate of symptomatic infected individuals to the quarantined infected class. By changing these factors, two optimal policies are successfully designed. This study has two main scientific contributions that are: (1) This is pioneer research that proposes policies regarding COVID-19, (2) This is also the first research that addresses COVID-19 and considers its economic consequences through a multi-objective evolutionary algorithm. Numerical simulations conspicuously demonstrate that by applying the proposed optimal policies, governments could find useful and practical ways for control of the disease.
    Keywords covid19
    Language English
    Publishing date 2020-05-16
    Publishing country England
    Document type Journal Article
    ZDB-ID 2003919-0
    ISSN 1873-2887 ; 0960-0779
    ISSN (online) 1873-2887
    ISSN 0960-0779
    DOI 10.1016/j.chaos.2020.109883
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  6. Article ; Online: On-court evaluation of selected key indicators of fitness among elite basketball players.

    Gandomkar, Amin / Eslami, Mansour / Yousefpour, Rohollah / Fayyaz Movaghar, Afshin

    The Journal of sports medicine and physical fitness

    2021  Volume 62, Issue 1, Page(s) 39–46

    Abstract: Background: The development of the norm of functional variables of fitness as a national database was considered the most important criterion of success in basketball. The current study aims to investigate the performance and skill-related determinants ... ...

    Abstract Background: The development of the norm of functional variables of fitness as a national database was considered the most important criterion of success in basketball. The current study aims to investigate the performance and skill-related determinants of physical fitness.
    Methods: Forty-three elite basketball players (including 14 centers, 15 forward and 14 guard players) participated in this cross-sectional study. The biomechanical parameters of the vertical jump and on-court tests including 20-meter dash, 4×9m agility, 10×20 m shuttle run, repeated side hop, were evaluated. The values of these parameters were compared between different posts using MANOVA and Tukey Post hoc tests in SPSS software (P≤0.05).
    Results: The norm of physical fitness parameters was obtained by determining the percentage points of 0-10%, 10-25%, 25-50%, 50-75%, 75-90% and 90-100%. Furthermore, peak vertical jump velocity and relative jump power were significantly higher in the guards and forwards compared to the centers (P=0.007 and P=0.027, respectively). The forwards showed significantly higher mean agility, repeated shuttle running, and EUR compared to the centers (P<0.001, P=0.020 and P=0.04, respectively). The repeated side jump was significantly lower in the centers by 8% compared to the guards (P=0.01).
    Conclusions: It was concluded that exercises for guards with a stronger emphasis on agility and explosiveness (plyometric exercises) in combination with aerobic fitness should be considered. Center players can benefit from resistance training in combination with jumping skills. Speed endurance and anaerobic power in skill related maneuvers are parameters of the players' poor performance in all three positions.
    MeSH term(s) Athletic Performance ; Basketball ; Cross-Sectional Studies ; Humans ; Physical Fitness ; Resistance Training ; Running
    Language English
    Publishing date 2021-02-22
    Publishing country Italy
    Document type Journal Article
    ZDB-ID 410823-1
    ISSN 1827-1928 ; 0022-4707
    ISSN (online) 1827-1928
    ISSN 0022-4707
    DOI 10.23736/S0022-4707.21.12144-9
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  7. Book ; Online: GP+

    Yousefpour, Amin / Foumani, Zahra Zanjani / Shishehbor, Mehdi / Mora, Carlos / Bostanabad, Ramin

    A Python Library for Kernel-based learning via Gaussian Processes

    2023  

    Abstract: In this paper we introduce GP+, an open-source library for kernel-based learning via Gaussian processes (GPs) which are powerful statistical models that are completely characterized by their parametric covariance and mean functions. GP+ is built on ... ...

    Abstract In this paper we introduce GP+, an open-source library for kernel-based learning via Gaussian processes (GPs) which are powerful statistical models that are completely characterized by their parametric covariance and mean functions. GP+ is built on PyTorch and provides a user-friendly and object-oriented tool for probabilistic learning and inference. As we demonstrate with a host of examples, GP+ has a few unique advantages over other GP modeling libraries. We achieve these advantages primarily by integrating nonlinear manifold learning techniques with GPs' covariance and mean functions. As part of introducing GP+, in this paper we also make methodological contributions that (1) enable probabilistic data fusion and inverse parameter estimation, and (2) equip GPs with parsimonious parametric mean functions which span mixed feature spaces that have both categorical and quantitative variables. We demonstrate the impact of these contributions in the context of Bayesian optimization, multi-fidelity modeling, sensitivity analysis, and calibration of computer models.
    Keywords Computer Science - Machine Learning ; Statistics - Machine Learning
    Publishing date 2023-12-12
    Publishing country us
    Document type Book ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  8. Article ; Online: Optimal policies for control of the novel coronavirus disease (COVID-19) outbreak

    Yousefpour, Amin / Jahanshahi, Hadi / Bekiros, Stelios

    Chaos, Solitons & Fractals

    2020  Volume 136, Page(s) 109883

    Keywords General Mathematics ; covid19
    Language English
    Publisher Elsevier BV
    Publishing country us
    Document type Article ; Online
    ZDB-ID 2003919-0
    ISSN 1873-2887 ; 0960-0779
    ISSN (online) 1873-2887
    ISSN 0960-0779
    DOI 10.1016/j.chaos.2020.109883
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  9. Article ; Online: Application of reinforcement learning for effective vaccination strategies of coronavirus disease 2019 (COVID-19).

    Beigi, Alireza / Yousefpour, Amin / Yasami, Amirreza / Gómez-Aguilar, J F / Bekiros, Stelios / Jahanshahi, Hadi

    European physical journal plus

    2021  Volume 136, Issue 5, Page(s) 609

    Abstract: Since December 2019, the new coronavirus has raged in China and subsequently all over the world. From the first days, researchers have tried to discover vaccines to combat the epidemic. Several vaccines are now available as a result of the contributions ... ...

    Abstract Since December 2019, the new coronavirus has raged in China and subsequently all over the world. From the first days, researchers have tried to discover vaccines to combat the epidemic. Several vaccines are now available as a result of the contributions of those researchers. As a matter of fact, the available vaccines should be used in effective and efficient manners to put the pandemic to an end. Hence, a major problem now is how to efficiently distribute these available vaccines among various components of the population. Using mathematical modeling and reinforcement learning control approaches, the present article aims to address this issue. To this end, a deterministic Susceptible-Exposed-Infectious-Recovered-type model with additional vaccine components is proposed. The proposed mathematical model can be used to simulate the consequences of vaccination policies. Then, the suppression of the outbreak is taken to account. The main objective is to reduce the effects of Covid-19 and its domino effects which stem from its spreading and progression. Therefore, to reach optimal policies, reinforcement learning optimal control is implemented, and four different optimal strategies are extracted. Demonstrating the efficacy of the proposed methods, finally, numerical simulations are presented.
    Language English
    Publishing date 2021-05-31
    Publishing country Germany
    Document type Journal Article
    ISSN 2190-5444
    ISSN (online) 2190-5444
    DOI 10.1140/epjp/s13360-021-01620-8
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  10. Article: Electrodeposition of TiO

    Yousefpour, Mardali / Shokuhy, Amin

    Superlattices and microstructures

    2014  Volume 51, Issue 6, Page(s) 842–853

    Abstract: ... ...

    Abstract TiO
    Language English
    Publishing date 2014-09-30
    Publishing country England
    Document type Journal Article
    ZDB-ID 1471791-8
    ISSN 1096-3677 ; 0749-6036
    ISSN (online) 1096-3677
    ISSN 0749-6036
    DOI 10.1016/j.spmi.2012.03.024
    Database MEDical Literature Analysis and Retrieval System OnLINE

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