Ebrahim Karami

Ebrahim Karami

Memorial University of Newfoundland, St. John's, Newfoundland and Labrador, Canada
orcid

Research Focus & Metrics

Academic Career Length

24Years (2003-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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16 July 2023 in Information
Verified
Journal Article
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ZJzahra zara Jafari
zahra zara Jafari
Ebrahim KaramiEbrahim Karami
Ebrahim Karami
The prompt and accurate diagnosis of breast lesions, including the distinction between cancer, non-cancer, and suspicious cancer, plays a crucial role in the prognosis of breast cancer. In this paper, we introduce a novel method based on feature extraction and reduction for the detection of breast cancer in mammography images. First, we extract features from multiple pre-trained convolutional neural network (CNN) models, and then concatenate them. The most informative features are selected based on their mutual information with the target variable. Subsequently, the selected features can be classified using a machine learning algorithm. We evaluate our approach using four different machine learning algorithms: neural network (NN), k-nearest neighbor (kNN), random forest (RF), and support vector machine (SVM). Our results demonstrate that the NN-based classifier achieves an impressive accuracy of 92% on the RSNA dataset. This dataset is newly introduced and includes two views as well as additional features like age, which contributed to the improved performance. We compare our proposed algorithm with state-of-the-art methods and demonstrate its superiority, particularly in terms of accuracy and sensitivity. For the MIAS dataset, we achieve an accuracy as high as 94.5%, and for the DDSM dataset, an accuracy of 96% is attained. These results highlight the effectiveness of our method in accurately diagnosing breast lesions and surpassing existing approaches.

12 November 2007 in IEEE Transactions on Communications
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Journal Article
Closed access
Ebrahim KaramiEbrahim Karami
Ebrahim Karami
In this paper, the tracking performance analysis of the least squares (LS) multiple-input multiple-output (MIMO) channel estimation and tracking algorithm is presented. MIMO channel estimation is a novel application of the LS algorithm that presents near-optimum performance by Karami and Shiva in 2003 and 2006. In this paper, the mean square error (MSE) of tracking of the LS MIMO channel estimator algorithm is derived as a closed-form function of the Doppler shift, forgetting factor, channel rank, and the length of training sequences. In the analysis, all training symbols are considered as randomly generated equal-power vectors on the unit circle, or in other words, phase-shift keying (PSK) signaling. By evaluating this function, some insights into the tracking behavior of the LS MIMO channel estimator are achieved. Then, the calculated tracking error is compared with the tracking error derived from Monte Carlo simulation for quaternary-PSK-based training signals to verify the validation of the presented analysis. Finally, the optimum forgetting factor is derived to minimize the error function, and it is shown that the optimum forgetting factor is highly dependent on the training length, Doppler shift, and Eb/No. Also, it is concluded that in low Eb/No values, the number of transmitter antennas has negligible effect on the optimal value of the forgetting factor.

2 November 2023 in Biomimetics
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Ramin Yousefpour ShahrivarRamin Yousefpour Shahrivar
Ramin Yousefpour Shahrivar
FKFatemeh Karami
Fatemeh Karami
Ebrahim KaramiEbrahim Karami
Ebrahim Karami
Fetal development is a critical phase in prenatal care, demanding the timely identification of anomalies in ultrasound images to safeguard the well-being of both the unborn child and the mother. Medical imaging has played a pivotal role in detecting fetal abnormalities and malformations. However, despite significant advances in ultrasound technology, the accurate identification of irregularities in prenatal images continues to pose considerable challenges, often necessitating substantial time and expertise from medical professionals. In this review, we go through recent developments in machine learning (ML) methods applied to fetal ultrasound images. Specifically, we focus on a range of ML algorithms employed in the context of fetal ultrasound, encompassing tasks such as image classification, object recognition, and segmentation. We highlight how these innovative approaches can enhance ultrasound-based fetal anomaly detection and provide insights for future research and clinical implementations. Furthermore, we emphasize the need for further research in this domain where future investigations can contribute to more effective ultrasound-based fetal anomaly detection.

1 May 2015
Verified
Conference Paper
Closed access
Ebrahim KaramiEbrahim Karami
Ebrahim Karami
ODOctavia A. Dobre
Octavia A. Dobre
NANikhil Adnani
Nikhil Adnani
Automatic signal identification (ASI) has various military and commercial applications, such as spectrum surveillance and cognitive radio. In this paper, a novel ASI algorithm is proposed for the identification of GSM and LTE signals, which is based on the pilot-induced second-order cyclostationarity. The proposed algorithm provides a very good performance at low signal-to-noise ratios and short observation times, with no need for channel estimation, and timing and frequency synchronization. Simulations and off-the-air signals acquired with the ThinkRF WSA4000 receiver are used to confirm the findings.

22 March 2017 in IEEE Transactions on Signal Processing
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Journal Article
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MMMostafa Mohammadkarimi
Mostafa Mohammadkarimi
Ebrahim KaramiEbrahim Karami
Ebrahim Karami
ODOctavia A. Dobre
Octavia A. Dobre
MWMoe Z. Win
Moe Z. Win
Detection of the number of transmit antennas plays an important role in the design of adaptive multiantenna wireless communication systems. This paper develops a detection algorithm based on second- and fourth-order statistics of the received signal and time-varying nature of the wireless channel. In contrast to existing feature-based algorithms, the proposed algorithm does not require a priori information about the transmitted signals, such as coding scheme, modulation type, and pilot patterns. Unlike information-theoretic algorithms, it does not require the number of receive antennas to be larger than that of transmit antennas. In fact, the proposed algorithm is capable of operating with a single receive antenna even for large numbers of transmit antennas. The performance analysis of the proposed algorithm is provided, and the results are verified through simulations. The algorithm exhibits a good performance over a wide range of signal-to-noise ratios, and is robust to the carrier frequency and timing offsets.

20 March 2006 in EURASIP Journal on Wireless Communications and Networking
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Journal Article
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Ebrahim KaramiEbrahim Karami
Ebrahim Karami
MSMohsen Shiva
Mohsen Shiva