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mohammadzade--hoda
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Hardware Implementation of Wearable Cuff-less Blood Pressure Monitoring Module
,
M.Sc. Thesis
Sharif University of Technology
;
Shabany, Mahdi
(Supervisor)
;
Mohammadzade, Hoda
(Supervisor)
Abstract
Hypertension precvalence is 24 and 20.5 percent in men and women, respectively. Continuous Blood Pressure monitoring can provide invaluable information about individuals’ health conditions. However, BP is conventionally measured using inconvenient cuff-based instruments, which prevents continuous BP monitoring. This work presents an efficient algorithm, based on the Pulse Arrival Time (PAT), extracted from Electrocardiogram (ECG) and Photopletysmograph (PPG), for the continuous and cuff-less estimation of the Systolic Blood Pressure (SBP), Diastolic Blood Pressure (DBP), and Mean Arterial Pressure (MAP) values. Methods: The proposed framework estimates the BP values through processing vital...
Sparsness embedding in bending of space and time; a case study on unsupervised 3D action recognition
, Article Journal of Visual Communication and Image Representation ; Volume 66 , January , 2020 ; Tabejamaat, M ; Sharif University of Technology
Academic Press Inc
2020
Abstract
Human action recognition from skeletal data is one of the most popular topics in computer vision which has been widely studied in the literature, occasionally with some very promising results. However, being supervised, most of the existing methods suffer from two major drawbacks; (1) too much reliance on massive labeled data and (2) high sensitivity to outliers, which in turn hinder their applications in such real-world scenarios as recognizing long-term and complex movements. In this paper, we propose a novel unsupervised 3D action recognition method called Sparseness Embedding in which the spatiotemporal representation of action sequences is nonlinearly projected into an unwarped feature...
Human Action Recognition Using Depthmap Image Sequences for Abnormal Event Detection
,
M.Sc. Thesis
Sharif University of Technology
;
Mohammadzadeh, Hoda
(Supervisor)
Abstract
The human action recognition is one of the most important concepts of computer vision in recent decades. Most of the two dimensional methods in this field are facing serious challenges such as occlusion and missing the third dimension of data. Development of depth sensors has made easy access to tracking people and 3D positions of human body joints. This Thesis proposes a new method of action recognition that utilizes the position of joints obtained by Kinect sensor. The learning stage uses Fisher Linear Discriminant Analysis (LDA) to construct discriminant feature space. Two types of distances, i.e., Euclidean and Mahalanobis, are used for recognizing the states. Also, Hidden Markov Model...
Cross-Domain EEG-Based Emotion Recognition
, M.Sc. Thesis Sharif University of Technology ; Mohammadzadeh, Hoda (Supervisor)
Abstract
The non-stationary nature of brain activity signals and their many inter-subject differences have created many challenges in the practical applications of emotion recognition based on electroencephalogram (EEG) signals, such as brain-computer interfaces. In such a way, the use of traditional classifiers in classifying these signals leads to a significant decrease in accuracy when applying the classifier to a new subject. Domain Adaptation methods seem to be an effective way to solve this problem by minimizing the difference between the EEG signals of different subjects. But in the basic techniques for domain adaptation, looking at all subjects' data in the same look causes the loss of a part...
Pixel-level alignment of facial images for high accuracy recognition using ensemble of patches
, Article Journal of the Optical Society of America A: Optics and Image Science, and Vision ; Volume 35, Issue 7 , 2018 , Pages 1149-1159 ; 10847529 (ISSN) ; Sayyafan, A ; Ghojogh, B ; Sharif University of Technology
OSA - The Optical Society
2018
Abstract
The variation of pose, illumination, and expression continues to make face recognition a challenging problem. As a pre-processing step in holistic approaches, faces are usually aligned by eyes. The proposed method tries to perform a pixel alignment rather than eye alignment by mapping the geometry of faces to a reference face while keeping their own textures. The proposed geometry alignment not only creates a meaningful correspondence among every pixel of all faces, but also removes expression and pose variations effectively. The geometry alignment is performed pixel-wise, i.e., every pixel of the face is corresponded to a pixel of the reference face. In the proposed method, the information...
High accuracy farsi language character segmentation and recognition
, Article 27th Iranian Conference on Electrical Engineering, ICEE 2019, 30 April 2019 through 2 May 2019 ; 2019 , Pages 1692-1698 ; 9781728115085 (ISBN) ; Javaheripi, M ; Mohammadzade, H ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2019
Abstract
Despite many advances in optical character recognition in general, there are still serious challenges remaining in recognizing Farsi text. The main reason is the cursive nature of the letters in written Farsi, i.e., depending on the position of a letter within a word, it might join to its neighboring letters, which consequently changes the shape of the character. As a result, each letter can have up to four different character shapes. In addition to the problem of segmenting the characters, the increased number of characters makes the recognition task even more challenging. This paper introduces a complete framework for character recognition, including a method for segmenting the characters...
Automated Lip-Reading robotic system based on convolutional neural network and long short-term memory
, Article 13th International Conference on Social Robotics, ICSR 2021, 10 November 2021 through 13 November 2021 ; Volume 13086 LNAI , 2021 , Pages 73-84 ; 03029743 (ISSN) ; 9783030905248 (ISBN) ; Taheri, A ; Mohammadzade, H ; Sharif University of Technology
Springer Science and Business Media Deutschland GmbH
2021
Abstract
In Iranian Sign Language (ISL), alongside the movement of fingers/arms, the dynamic movement of lips is also essential to perform/recognize a sign completely and correctly. In a follow up of our previous studies in empowering the RASA social robot to interact with individuals with hearing problems via sign language, we have proposed two automated lip-reading systems based on DNN architectures, a CNN-LSTM and a 3D-CNN, on the robotic system to recognize OuluVS2 database words. In the first network, CNN was used to extract static features, and LSTM was used to model temporal dynamics. In the second one, a 3D-CNN network was used to extract appropriate visual and temporal features from the...
Alzheimer’s disease early diagnosis using manifold-based semi-supervised learning
, Article Brain Sciences ; Volume 7, Issue 8 , 2017 ; 20763425 (ISSN) ; Habibollahi Saatlou, F ; Mohammadzade, H ; Sharif University of Technology
2017
Abstract
Alzheimer’s disease (AD) is currently ranked as the sixth leading cause of death in the United States and recent estimates indicate that the disorder may rank third, just behind heart disease and cancer, as a cause of death for older people. Clearly, predicting this disease in the early stages and preventing it from progressing is of great importance. The diagnosis of Alzheimer’s disease (AD) requires a variety of medical tests, which leads to huge amounts of multivariate heterogeneous data. It can be difficult and exhausting to manually compare, visualize, and analyze this data due to the heterogeneous nature of medical tests, therefore, an efficient approach for accurate prediction of the...
Blood pressure estimation using photoplethysmogram signal and its morphological features
, Article IEEE Sensors Journal ; Volume 20, Issue 8 , 2020 , Pages 4300-4310 ; Ahmadi, M. M ; Mohammadzade, H ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2020
Abstract
In this paper, we present a machine learning model to estimate the blood pressure (BP) of a person using only his photoplethysmogram (PPG) signal. We propose algorithms to better detect some critical points of the PPG signal, such as systolic and diastolic peaks, dicrotic notch and inflection point. These algorithms are applicable to different PPG signal morphologies and improve the precision of feature extraction. We show that the logarithm of dicrotic notch reflection index, the ratio of low-to high-frequency components of heart rate (HR) variability signal, and the product of HR multiplied by the modified Normalized Pulse Volume (mNPV) are the key features in accurately estimating the BP...
Blood Pressure Estimation Using a PPG Signal Recorded From the Fingertip of a Hand Moving in the Sagittal Plane
, Article IEEE Sensors Journal ; Volume 23, Issue 15 , 2023 , Pages 17751-17760 ; 1530437X (ISSN) ; Ahmadi, M. M ; Mohammadzade, H ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2023
Abstract
In this article, we present a new photoplethysmogram (PPG)-based blood pressure (BP) estimation approach, in which the PPG recording site (fingertip) is not in a standstill position but swings up and down in the sagittal plane during the recording. The upward and downward movements of the recording site result in useful morphological changes in the PPG signal, which can be used to better estimate BP. To investigate the effect of the vertical hand movement on the shape of the PPG signal, we first devised a PPG recording hardware and used it to collect a dataset consisting of PPG signals recorded from 120 subjects. Then, we utilized machine-learning models to estimate BP using the extracted...
Auto-selection of space-time Interest Points for Action Recognition
Application in Fisherposes Method
,
M.Sc. Thesis
Sharif University of Technology
;
Mohammadzadeh, Narges Hoda
(Supervisor)
Abstract
In this project, a novel action recognition method, named Fisherposes, is proposed, which is improved by several space-time (spatio-temporal) methods afterwards. The proposed method utilizes skeleton data obtained from Kinect sensor. First, pre-processing is performed in which the scales of bodies are canceled and the skeletons become aligned in order to make the method robust to location, orientation, and scale of people. In Fisherposes method, every action is defined as a sequence of body poses. Using the training samples for the poses, a Fisher subspace is created which we name it Fisherposes. Moreover, a novel distance measuring function, named regularized Mahalanobis distance, is...
Cuff-less high-accuracy calibration-free blood pressure estimation using pulse transit time
, Article Proceedings - IEEE International Symposium on Circuits and Systems, 24 May 2015 through 27 May 2015 ; Volume 2015-July , 2015 , Pages 1006-1009 ; 02714310 (ISSN) ; 9781479983919 (ISBN) ; Kiani, M.M ; Mohammadzade, H ; Shabany, M ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2015
Abstract
Recently a few methods have been proposed in the literature for non-invasive cuff-less estimation of systolic and diastolic blood pressures. One of the most prominent methods is to use the Pulse Transit Time (PTT). Although it is proven that PTT has a strong correlation with the systolic and diastolic blood pressures, this relation is highly dependent to each individuals physiological properties. Therefore, it requires per person calibration for accurate and reliable blood pressure estimation from PTT, which is a big drawback. To alleviate this issue, in this paper, a novel method is proposed for accurate and reliable estimation of blood pressure that is calibration-free. This goal is...
Multifaceted service identification: Process, requirement and data
, Article Computer Science and Information Systems ; Volume 13, Issue 2 , 2016 , Pages 335-358 ; 18200214 (ISSN) ; Parsa, S ; Mohammadzade Lajevardi, A ; Sharif University of Technology
ComSIS Consortium
2016
Abstract
Service Identification is one of the most important phases in serviceoriented development methodologies. Although several service identification methods tried to identify services automatically or semi-automatically, various aspects of business domain are not taken into account simultaneously. To overcome this issue, three strategies from three different aspects of business domain are combined for semi-automated identification of services in this article. At first, the tasks interconnections within the business processes are considered. Then, based on the common supporting requirements, another tasks dependency has been determined and finally, regarding the significant impact of data in...
Critical object recognition in millimeter-wave images with robustness to rotation and scale
, Article Journal of the Optical Society of America A: Optics and Image Science, and Vision ; Volume 34, Issue 6 , 2017 , Pages 846-855 ; 10847529 (ISSN) ; Ghojogh, B ; Faezi, S ; Shabany, M ; Sharif University of Technology
OSA - The Optical Society
2017
Abstract
Locating critical objects is crucial in various security applications and industries. For example, in security applications, such as in airports, these objects might be hidden or covered under shields or secret sheaths. Millimeter-wave images can be utilized to discover and recognize the critical objects out of the hidden cases without any health risk due to their non-ionizing features. However, millimeter-wave images usually have waves in and around the detected objects, making object recognition difficult. Thus, regular image processing and classification methods cannot be used for these images and additional pre-processings and classification methods should be introduced. This paper...
Markhor: malware detection using fuzzy similarity of system call dependency sequences
, Article Journal of Computer Virology and Hacking Techniques ; Volume 18, Issue 2 , 2022 , Pages 81-90 ; 22638733 (ISSN) ; Parsa, S ; Amiri, M. J ; Sharif University of Technology
Springer-Verlag Italia s.r.l
2022
Abstract
Static malware detection approaches are time-consuming and cannot deal with code obfuscation techniques. Dynamic malware detection approaches, on the other hand, address these two challenges, however, suffer from behavioral ambiguity, such as the system calls obfuscation. In this paper, we introduce Markhor, a dynamic and behavior-based malware detection approach. Markhor uses system call data dependency and system call control dependency sequences to create a weighted list of malicious patterns. The list is then used to determine the malicious processes. Next, the similarity of a file system call sequences to a malicious pattern is extracted based on a fuzzy algorithm and the file nature is...
Numerical Study of Surface Growth in Presence of Height Dependent Noise using Higher order Approximation Algorithms
, M.Sc. Thesis Sharif University of Technology ; Moghimi-Araghi, Saman (Supervisor)
Abstract
Surface growth is one of subjects that has many applications in industry, and its deep recognition in physics remarkably helps us in understanding of critical systems. There are various approaches for analyzing this phenomenon, one of the most important of which is differential equations.In this approach, with respect to surface properties, a partial differential equation is introduced, and the critical exponents are obtained by solving it. In this thesis, after studying several continuum equations such as: Edwards-Wilkinson, KPZ, and Wolf-Villain equation,we provide numerical solutions of these equations in presence of height dependent noise. The role of noise in stochastic differential...
Cysteic acid grafted to magnetic graphene oxide as a promising recoverable solid acid catalyst for the synthesis of diverse 4H-chromene
, Article Scientific Reports ; Volume 10, Issue 1 , December , 2020 ; Eslami, M ; Hoda, G ; Sharif University of Technology
Nature Research
2020
Abstract
4H-chromenes play a significant role in natural and pharmacological products. Despite continuous advances in the synthesis methodology of these compounds, there is still a lack of a green and efficient method. In this study, we have designed cysteic acid chemically attached to magnetic graphene oxide (MNPs·GO-CysA) as an efficient and reusable solid acid catalyst to synthesize 4H-chromene skeletons via a one-pot three components reaction of an enolizable compound, malononitrile, an aldehyde or isatin, and a mixture of water–ethanol as a green solvent. This new heterogeneous catalyst provides desired products with a good to excellent yield, short time, and mild condition. This procedure...
Temporal Analysis of Functional Brain Connectivity Using EEG Signals
, M.Sc. Thesis Sharif University of Technology ; Mohammadzadeh, Narges Hoda (Supervisor)
Abstract
Human has different emotions such as happiness, sadness, anger, etc. Recognizing these emotions plays an important role in human-machine interface. Emotion recognition can be divided into approaches, physiological and non-physiological signals. Non-physiological signals include facial expressions, body gesture, and voice, and physiological signals include electroencephalograph (EEG), electrocardiograph (ECG), and functional magnetic resonance imaging (fMRI). EEG signal has been absorbed a lot of attention in emotion recognition because recording of EEG signal is easy and it is non-invasive. Analysis of connectivity and interaction between different areas of the brain can provide useful...
Cuffless blood pressure estimation algorithms for continuous health-care monitoring
, Article IEEE Transactions on Biomedical Engineering ; Volume 64, Issue 4 , 2017 , Pages 859-869 ; 00189294 (ISSN) ; Kiani, M. M ; Mohammadzade, H ; Shabany, M ; Sharif University of Technology
IEEE Computer Society
2017
Abstract
Goal: Continuous blood pressure (BP) monitoring can provide invaluable information about individuals' health conditions. However, BP is conventionally measured using inconvenient cuff-based instruments, which prevents continuous BP monitoring. This paper presents an efficient algorithm, based on the pulse arrival time (PAT), for the continuous and cuffless estimation of the systolic BP, diastolic blood pressure (DBP), and mean arterial pressure (MAP) values. Methods: The proposed framework estimates the BP values through processing vital signals and extracting two types of features, which are based on either physiological parameters or whole-based representation of vital signals. Finally,...
A fusion-based gender recognition method using facial images
, Article 26th Iranian Conference on Electrical Engineering, ICEE 2018, 8 May 2018 through 10 May 2018 ; 2018 , Pages 1493-1498 ; 9781538649169 (ISBN) ; Bagheri Shouraki, S ; Mohammadzade, H ; Iranmehr, E ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2018
Abstract
This paper proposes a fusion-based gender recognition method which uses facial images as input. Firstly, this paper utilizes pre-processing and a landmark detection method in order to find the important landmarks of faces. Thereafter, four different frameworks are proposed which are inspired by state-of-the-art gender recognition systems. The first framework extracts features using Local Binary Pattern (LBP) and Principal Component Analysis (PCA) and uses back propagation neural network. The second framework uses Gabor filters, PCA, and kernel Support Vector Machine (SVM). The third framework uses lower part of faces as input and classifies them using kernel SVM. The fourth framework uses...