Ashraf A. Khalaf

Dr. Ashraf A. Khalaf

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Research Focus & Metrics

Academic Career Length

30Years (1997-Present)

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

Representative Publications

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1 September 2019 in Magnetic Resonance Imaging
Verified
Journal Article
Closed access
Mahmoud Khaled Abd-EllahMahmoud Khaled Abd-Ellah
Mahmoud Khaled Abd-Ellah
Ali Ismail AwadAli Ismail Awad
Ali Ismail Awad
Ashraf A. KhalafAshraf A. Khalaf
Ashraf A. Khalaf
HHHesham Hamed
Hesham Hamed

30 September 2018 in EURASIP Journal on Image and Video Processing
Verified
Journal Article
Open access
PDF file
Mahmoud Khaled Abd-EllahMahmoud Khaled Abd-Ellah
Mahmoud Khaled Abd-Ellah
Ali Ismail AwadAli Ismail Awad
Ali Ismail Awad
Ashraf A. KhalafAshraf A. Khalaf
Ashraf A. Khalaf
HHHesham F. A. Hamed
Hesham F. A. Hamed
Brain tumour is a serious disease, and the number of people who are dying due to brain tumours is increasing. Manual tumour diagnosis from magnetic resonance images (MRIs) is a time consuming process and is insufficient for accurately detecting, localizing, and classifying the tumour type. This research proposes a novel two-phase multi-model automatic diagnosis system for brain tumour detection and localization. In the first phase, the system structure consists of preprocessing, feature extraction using a convolutional neural network (CNN), and feature classification using the error-correcting output codes support vector machine (ECOC-SVM) approach. The purpose of the first system phase is to detect brain tumour by classifying the MRIs into normal and abnormal images. The aim of the second system phase is to localize the tumour within the abnormal MRIs using a fully designed five-layer region-based convolutional neural network (R-CNN). The performance of the first phase was assessed using three CNN models, namely, AlexNet, Visual Geometry Group (VGG)-16, and VGG-19, and a maximum detection accuracy of 99.55% was achieved with AlexNet using 349 images extracted from the standard Reference Image Database to Evaluate Response (RIDER) Neuro MRI database. The brain tumour localization phase was evaluated using 804 3D MRIs from the Brain Tumor Segmentation (BraTS) 2013 database, and a DICE score of 0.87 was achieved. The empirical work proved the outstanding performance of the proposed deep learning-based system in tumour detection compared to other non-deep-learning approaches in the literature. The obtained results also demonstrate the superiority of the proposed system concerning both tumour detection and localization.

18 February 2021 in IEEE Access
Verified
Journal Article
Open access
OWOsama Fouad Abdel Wahab
Osama Fouad Abdel Wahab
Ashraf A. KhalafAshraf A. Khalaf
Ashraf A. Khalaf
AHAziza I. Hussein
Aziza I. Hussein
HHHesham F. A. Hamed
Hesham F. A. Hamed
Data compression is an important part of information security because compressed data is more secure and easy to handle. Effective data compression technology creates efficient, secure, and easy-to-connect data. There are two types of compression algorithm techniques, lossy and lossless. These technologies can be used in any data format such as text, audio, video, or image file. The main objective of this study was to reduce the physical space on the various storage media and reduce the time of sending data over the Internet with a complete guarantee of encrypting this data and hiding it from intruders. Two techniques are implemented, with data loss (Lossy) and without data loss (Lossless). In the proposed paper a hybrid data compression algorithm increases the input data to be encrypted by RSA (Rivest-Shamir-Adleman) cryptography method to enhance the security level and it can be used in executing lossy and lossless compacting Steganography methods. This technique can be used to decrease the amount of every transmitted data aiding fast transmission while using slow internet or take a small space on different storage media. The plain text is compressed by the Huffman coding algorithm, and also the cover image is compressed by Discrete wavelet transform DWT based that compacts the cover image through lossy compression in order to reduce the cover image's dimensions. The least significant bit LSB will then be used to implant the encrypted data in the compacted cover image. We evaluated that system on criteria such as percentage Savings percentage, Compression Time, Compression Ratio, Bits per pixel, Mean Squared Error, Peak Signal to Noise Ratio, Structural Similarity Index, and Compression Speed. This system shows a high-level performance and system methodology compared to other systems that use the same methodology.

18 March 2020 in Multimedia Tools and Applications
Verified
Journal Article
Closed access
PDF file
MEMoahmed Elaskily
Moahmed Elaskily
HEHeba A. Elnemr
Heba A. Elnemr
ASAhmed Sedik
Ahmed Sedik
MDMohamed Dessouky
Mohamed Dessouky
GBGhada El banby
Ghada El banby
FEFathi Abd El-Samie
Fathi Abd El-Samie

22 December 2020 in Microscopy Research and Technique
Verified
Journal Article
Closed access
PDF file
NENoha Elhag
Noha Elhag
ASAhmed Sedik
Ahmed Sedik
WEWalid El-Shafai
Walid El-Shafai
HEHeba M. El‐Hoseny
Heba M. El‐Hoseny
Ashraf A. KhalafAshraf A. Khalaf
Ashraf A. Khalaf
GEGhada M. El‐Banby
Ghada M. El‐Banby

1 September 2019 in Results in Physics
Verified
Journal Article
Open access
NANazmi Azzam
Nazmi Azzam
MHMahmoud M. Hamed
Mahmoud M. Hamed
Ashraf A. KhalafAshraf A. Khalaf
Ashraf A. Khalaf
AAAbdulaziz Alsayyari
Abdulaziz Alsayyari
SES. El-Rabaie
S. El-Rabaie