211 research outputs found
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Evaluation and analysis of hybrid intelligent pattern recognition techniques for speaker identification
This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University.The rapid momentum of the technology progress in the recent years has led to a tremendous rise in the use of biometric authentication systems. The objective of this research is to investigate the problem
of identifying a speaker from its voice regardless of the content (i.e.
text-independent), and to design efficient methods of combining face and voice in producing a robust authentication system.
A novel approach towards speaker identification is developed using
wavelet analysis, and multiple neural networks including Probabilistic
Neural Network (PNN), General Regressive Neural Network (GRNN)and Radial Basis Function-Neural Network (RBF NN) with the AND
voting scheme. This approach is tested on GRID and VidTIMIT cor-pora and comprehensive test results have been validated with state-
of-the-art approaches. The system was found to be competitive and it improved the recognition rate by 15% as compared to the classical Mel-frequency Cepstral Coe±cients (MFCC), and reduced the recognition time by 40% compared to Back Propagation Neural Network (BPNN), Gaussian Mixture Models (GMM) and Principal Component Analysis (PCA).
Another novel approach using vowel formant analysis is implemented using Linear Discriminant Analysis (LDA). Vowel formant based speaker identification is best suitable for real-time implementation and requires only a few bytes of information to be stored for each speaker, making it both storage and time efficient. Tested on GRID and Vid-TIMIT, the proposed scheme was found to be 85.05% accurate when Linear Predictive Coding (LPC) is used to extract the vowel formants, which is much higher than the accuracy of BPNN and GMM. Since the proposed scheme does not require any training time other than creating a small database of vowel formants, it is faster as well. Furthermore, an increasing number of speakers makes it di±cult for BPNN and GMM to sustain their accuracy, but the proposed score-based methodology stays almost linear.
Finally, a novel audio-visual fusion based identification system is implemented using GMM and MFCC for speaker identi¯cation and PCA for face recognition. The results of speaker identification and face recognition are fused at different levels, namely the feature, score and decision levels. Both the score-level and decision-level (with OR voting) fusions were shown to outperform the feature-level fusion in terms of accuracy and error resilience. The result is in line with the distinct nature of the two modalities which lose themselves when combined at the feature-level. The GRID and VidTIMIT test results validate that
the proposed scheme is one of the best candidates for the fusion of
face and voice due to its low computational time and high recognition accuracy
“THE EFFECT OF THE PERCEIVED USEFULNESS OF INSTAGRAM BEAUTY INFLUENCER ON THE ATTITUDE AND PURCHASING INTENTION OF YOUNG FEMALES”
There is an increasing interest about the topic of eWOM among marketing scholars. However, most of the studies focused on western contexts and there is a lack of studies about the impact of eWOM on consumers’ attitude and intentions in the Gulf region and Qatar specifically. Hence, this study aims to focus on a specific social media channel; Instagram, and examine the effect of influencers’ recommendations on women consumption of cosmetics products in Qatar. Two hundred and seven women completed an online questionnaire. PROCESS has been used to analyze data. Results indicate that, unlike what has been established in other contexts, the perceived usefulness of influencers and trust did not have a significant effect on brand attitude and only positively affected Purchase Intention. Therefore, this study adds the to the existing body of knowledge in this area and could guide social media managers use of Instagram influencers and help marketing professionals develop more efficient online advertising strategies
Evaluation Techniques for the Corrosion Resistance of Self-Healing Coatings
Self-healing coatings, materials that autonomically repair damage, are a method of extending the life of corrosion prevention coatings. The different types of self-healing coatings are briefly outlined. A review of the evaluation methods of the performance of self-healing coatings using electrochemical, surface and microscopy techniques are provided. Both global and local evaluation techniques are reviewed with emphasis on the most used electrochemical techniques as well as suggestions for alternative electrochemical techniques for self-healing coating evaluation
Effect of waste wax and chain structure on the mechanical and physical properties of polyethylene
The influence of adding waste wax, produced as a by-product of the low density polyethylene manufacturing process, on the thermal and mechanical properties of three types of polyethylene (PE), high-density polyethylene (HDPE), linear low-density polyethylene (LLDPE) and low-density polyethylene (LDPE), with 10, 20, 30 and 40wt.% was investigated. Polymer–wax mixing was effective with no apparent leakage of the wax during sample preparation, which was evident from the agreement between the theoretical and experimental values of enthalpy for all types of PE.The wax dispersion in the matrix strongly depends on the percentage of wax added to the polymer and the molecular structure of the polymer. It was found that increasing the wax content enhances the phase separation. LDPE undergoes less phase separation due to its highly branched structure composed of a network of short and long chain branches. The wax has no pronounced plasticising effect on the polymer. This is clearly manifested in LDPE as no change in the melting temperature occurred. LLDPE and HDPE were slightly affected by a high concentration of wax (30% and 40%). This is due to the non-uniform distribution of short chain branching along the LLDPE and HDPE main chains, which can interact with the wax structure.NPRP 4 – 465 – 2 – 173 from Qatar National Research Fund (a member of Qatar Foundation). Open Access funding from King Saud University
Emergent materials and industry 4.0 contribution toward pandemic diseases such as COVID-19
[No abstract available]Scopu
Melt processing and properties of Polyamide 6/Graphene nanoplatelet composites.
Graphene, due to its outstanding properties, has become the topic of much research activity in recent years. Much of that work has been on a laboratory scale however, if we are to introduce graphene into real product applications it is necessary to examine how the material behaves under industrial processing conditions. In this paper the melt processing of polyamide 6/graphene nanoplatelet composites via twin screw extrusion is investigated and structure-property relationships are examined for mechanical and electrical properties. Graphene nanoplatelets (GNPs) with two aspect ratios (700 and 1000) were used in order to examine the influence of particle dimensions on composite properties. It was found that the introduction of GNPs had a nucleating effect on polyamide 6 (PA6) crystallization and substantially increased crystallinity by up to 120% for a 20% loading in PA6. A small increase in crystallinity was observed when extruder screw speed increased from 50 rpm to 200 rpm which could be attributed to better dispersion and more nucleation sites for crystallization. A maximum enhancement of 412% in Young's modulus was achieved at 20 wt% loading of GNPs. This is the highest reported enhancement in modulus achieved to date for a melt mixed thermoplastic/GNPs composite. A further result of importance here is that the modulus continued to increase as the loading of GNPs increased even at 20 wt% loading and results are in excellent agreement with theoretical predictions for modulus enhancement. Electrical percolation was achieved between 10-15 wt% loading for both aspect ratios of GNPs with an increase in conductivity of approximately 6 orders of magnitude compared to the unfilled PA6.</p
Indoor visible light communication localization system utilizing received signal strength indication technique and trilateration method
Visible light communication (VLC) based on light-emitting diodes (LEDs) technology not only provides higher data rate for indoor wireless communications and offering room illumination but also has the potential for indoor localization. VLC-based indoor positioning using the received optical power levels from emitting LEDs is investigated. We consider both scenarios of line-of-sight (LOS) and LOS with non-LOS (LOSNLOS) positioning. The performance of the proposed system is evaluated under both noisy and noiseless channel as is the impact of different location codes on positioning error. The analytical model of the system with noise and the corresponding numerical evaluation for a range of signal-to-noise ratio (SNR) are presented. The results show that an accuracy of 12 dB
KinFit: A factual aerobic sport game with stimulation support
Overweight and obesity is a situation where a person has stacked too much fat that might affect negatively his/her health. Many people skip doing exercises due to several facts related to the encouragement, health-awareness, and time arrangement. Diverse aerobic video games have been proposed to help users in doing exercises. However, we observe some limitations in existing games. For instance, they don't give correct scores while wearing Arabic traditional suits, they don't consider showing immersive realistic scenes, and they don't stimulate users to do exercises and keeping them encouraged to play more. We propose in this paper an aerobic video game that displays real scenes of aerobic coaches and keeps the user notified about doing exercises. It is a kind of serious games that allows users to learn aerobic movements and practice with aerobic coaches. It contains several exercises in which each can be played on normal screen or in fully immersive virtual reality (VR). While the user is playing, he/she can see the playing score with the estimated amount of burned calories. It stores the time when the user plays to remind him/her about doing exercises again. The profound user studies demonstrated the usability and effectiveness of the proposed game. 2018 Kassel University Press GmbH.The authors would like to acknowledge that devices and equipment were provided by the Visual Computing Research Center, Department of Computer Science and Engineering, at Qatar University. This publication was supported by Qatar University Collaborative High Impact Grant QUHI-CENG-18/19-1. The content of this article and its quality are solely the responsibility of the authors and do not necessarily represent the official views of Qatar University.Scopu
Mussel-mimicking sulfobetaine-based copolymer with metal tunable gelation, self-healing and antibacterial capability
In the present study, the sulfobetaine-based copolymer bearing a dopamine functionality showed gel formation adjusted by the application of metal salts for gelation and various values of pH. Normally, the liquid-like solution of the sulfobetaine-based copolymer and metal cross-linkers is transformed to a gel-like state upon increasing the pH values in the presence of Fe3+ and Ti3+. Metal-induced coordination is reversible by means of the application of EDTA as a chelating agent. In the case of Ag+ ions, the gel is formed through a redox process accompanied with the oxidative coupling of the dopamine moieties and Ag0 particle formation. Mussel-mimicking and metal-dependent viscoelastic properties were observed for Fe3+, Ti3+, and Ag+ cross-linking agents, with additionally enhanced self-healing behavior in comparison with the covalently cross-linked IO4 − analogues. Antibacterial properties can be achieved both in solution and on the surface using the proper concentration of Ag+ ions used for gelation; thus, a tunable amount of the Ag0 particles are formed in the hydrogel. The cytotoxicity was elucidated by the both MTT assay on the NIH/3T3 fibroblast cell line and direct contact method using human dermal fibroblast cell (F121) and shows the non-toxic character of the synthesized copolymer. © 2017 The AuthorsQatar University [QUUG-CAM-2017-1]; Ministry of Education, Youth and Sports of the Czech Republic - Program NPU I [LO1504]; Maersk Oil R&TC Qatar project; Qatar National Research Fund (Qatar Foundation) [9 - 219-2-105
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