Nidhal Abdulaziz

Nidhal Abdulaziz


Research Focus & Metrics

Academic Career Length

20Years (2007-Present)

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

Representative Publications

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26 May 2021 in Applied Sciences
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Journal Article
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ACAbigail Copiaco
Abigail Copiaco
CRChristian Ritz
Christian Ritz
NANidhal Abdulaziz
Nidhal Abdulaziz
SFStefano Fasciani
Stefano Fasciani
Recent methodologies for audio classification frequently involve cepstral and spectral features, applied to single channel recordings of acoustic scenes and events. Further, the concept of transfer learning has been widely used over the years, and has proven to provide an efficient alternative to training neural networks from scratch. The lower time and resource requirements when using pre-trained models allows for more versatility in developing system classification approaches. However, information on classification performance when using different features for multi-channel recordings is often limited. Furthermore, pre-trained networks are initially trained on bigger databases and are often unnecessarily large. This poses a challenge when developing systems for devices with limited computational resources, such as mobile or embedded devices. This paper presents a detailed study of the most apparent and widely-used cepstral and spectral features for multi-channel audio applications. Accordingly, we propose the use of spectro-temporal features. Additionally, the paper details the development of a compact version of the AlexNet model for computationally-limited platforms through studies of performances against various architectural and parameter modifications of the original network. The aim is to minimize the network size while maintaining the series network architecture and preserving the classification accuracy. Considering that other state-of-the-art compact networks present complex directed acyclic graphs, a series architecture proposes an advantage in customizability. Experimentation was carried out through Matlab, using a database that we have generated for this task, which composes of four-channel synthetic recordings of both sound events and scenes. The top performing methodology resulted in a weighted F1-score of 87.92% for scalogram features classified via the modified AlexNet-33 network, which has a size of 14.33 MB. The AlexNet network returned 86.24% at a size of 222.71 MB.

29 December 2021 in Applied Sciences
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Journal Article
Open access
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AEAbeer Elkhouly
Abeer Elkhouly
AAAllan Melvin Andrew
Allan Melvin Andrew
Hasliza A RahimHasliza A Rahim
Hasliza A Rahim
NANidhal Abdulaziz
Nidhal Abdulaziz
MAMohamedfareq Abdulmalek
Mohamedfareq Abdulmalek
Shafiquzzaman SiddiqueeShafiquzzaman Siddiquee
Shafiquzzaman Siddiquee
The current practice of adjusting hearing aids (HA) is tiring and time-consuming for both patients and audiologists. Of hearing-impaired people, 40–50% are not satisfied with their HAs. In addition, good designs of HAs are often avoided since the process of fitting them is exhausting. To improve the fitting process, a machine learning (ML) unsupervised approach is proposed to cluster the pure-tone audiograms (PTA). This work applies the spectral clustering (SP) approach to group audiograms according to their similarity in shape. Different SP approaches are tested for best results and these approaches were evaluated by Silhouette, Calinski-Harabasz, and Davies-Bouldin criteria values. Kutools for Excel add-in is used to generate audiograms’ population, annotated using the results from SP, and different criteria values are used to evaluate population clusters. Finally, these clusters are mapped to a standard set of audiograms used in HA characterization. The results indicated that grouping the data in 8 groups or 10 results in ones with high evaluation criteria. The evaluation for population audiograms clusters shows good performance, as it resulted in a Silhouette coefficient >0.5. This work introduces a new concept to classify audiograms using an ML algorithm according to the audiograms’ similarity in shape.

11 July 2012 in European Journal of Engineering Education
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Journal Article
Closed access
SASarim Al-Zubaidy
Sarim Al-Zubaidy
NANidhal Abdulaziz
Nidhal Abdulaziz
RDReza Dashtpour
Reza Dashtpour
Recent scholarship references indicate that integration of the student body can result in an enhanced learning experience for students and also greater satisfaction. This paper reports the results of a case study whereby mechanical engineering students studying at a newly established branch campus in Dubai of a British university were exposed to vertical and horizontal integration. Different activities have been embedded to ensure that students integrated and worked together with their peers and colleagues at different levels. The implemented processes and practices led to improved academic achievements, which were better than those of a similar cohort of students where no effort had been made to integrate. The analysis revealed that cooperative learning and the degree of academic support provided by teachers are positively and directly correlated with academic as well as the students’ own sense of personal achievement. The results are discussed in light of previous research and with reference to the cultural context of the study.

1 January 2007
Verified
Conference Paper
Closed access
AGAbdullatif Glass
Abdullatif Glass
NANidhal Abdulaziz
Nidhal Abdulaziz
EBEesa Bastaki
Eesa Bastaki
A new slope line code for information transmission and storage has been proposed. The line code operates on the principle of slope coding. Two alternative slopes are used to transmit or store the binary information 1 s and 0 s. The decoder extracts the binary information from the received multilevel signal using slope comparison technique with slope violation detector from the incoming symbols. The encoder and decoder operation is described. A simulation of the encoder and decoder has been carried out using MultiSIM® software. The simulated results are in thorough agreement with the theory. The slope line code also meets the many desirable features of other line codes. This makes it attractive and suitable for data transmission and storage on different types of telecommunication networks and multimedia systems.

13 May 2021 in arXiv
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ACAbigail Copiaco
Abigail Copiaco
CRChristian Ritz
Christian Ritz
SFStefano Fasciani
Stefano Fasciani
NANidhal Abdulaziz
Nidhal Abdulaziz
Access to informative databases is a crucial part of notable research developments. In the field of domestic audio classification, there have been significant advances in recent years. Although several audio databases exist, these can be limited in terms of the amount of information they provide, such as the exact location of the sound sources, and the associated noise levels. In this work, we detail our approach on generating an unbiased synthetic domestic audio database, consisting of sound scenes and events, emulated in both quiet and noisy environments. Data is carefully curated such that it reflects issues commonly faced in a dementia patients environment, and recreate scenarios that could occur in real-world settings. Similarly, the room impulse response generated is based on a typical one-bedroom apartment at Hebrew SeniorLife Facility. As a result, we present an 11-class database containing excerpts of clean and noisy signals at 5-seconds duration each, uniformly sampled at 16 kHz. Using our baseline model using Continues Wavelet Transform Scalograms and AlexNet, this yielded a weighted F1-score of 86.24 percent.