An 'active' passive-filter topology for low power DC/AC inverters

This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University.This thesis presents a new output passive filter for voltage source inverter applications which is based on a shunt connected single tuned filter topology. The proposed circuit has the advantage of tracing harmonic components wherever its location in the frequency spectrum. The change in the harmonic location might be as a result of a change in the inverter operating frequency. Also, the proposed filter achieves harmonic reduction close to the traditional single tuned passive filter. In order to show the superiority of the proposed model, a comparison is introduced with other self tuning harmonic filters showing merits and drawbacks of each technique. The proposed circuit (when integrated in square wave inverter) has also shown a tremendous reduction in the switching losses in comparison with high frequency Pulse Width Modulation inverter. Mathematical analyses showing the design of the proposed filter together with extensive simulation results to verify the design are also introduced. The practical implementation of the system is presented and the results show excellent agreement with the theory and simulation. In order to appreciate the proposed filter a new method for classifying passive power filters is introduced. The review includes a comparison of these configurations showing their merit and drawbacks

Restrictive Voting Technique for Faces Spoofing Attack

Face anti-spoofing has become widely used due to the increasing use of biometric authentication systems that rely on facial recognition. It is a critical issue in biometric authentication systems that aim to prevent unauthorized access. In this paper, we propose a modified version of majority voting that ensembles the votes of six classifiers for multiple video chunks to improve the accuracy of face anti-spoofing. Our approach involves sampling sub-videos of 2 seconds each with a one-second overlap and classifying each sub-video using multiple classifiers. We then ensemble the classifications for each sub-video across all classifiers to decide the complete video classification. We focus on the False Acceptance Rate (FAR) metric to highlight the importance of preventing unauthorized access. We evaluated our method using the Replay Attack dataset and achieved a zero FAR. We also reported the Half Total Error Rate (HTER) and Equal Error Rate (EER) and gained a better result than most state-of-the-art methods. Our experimental results show that our proposed method significantly reduces the FAR, which is crucial for real-world face anti-spoofing applications

Cloud applications in language teaching: Examining pre-service teachers\u27 expertise, perceptions and integration

© 2017, IGI Global. This study examined pre-service teachers\u27 expertise, perceptions and integration of cloud applications in teaching of Arabic and English. Questionnaires and semi-structured interviews were used as data collection methods. The findings of the study specified that pre-service teachers did not own sufficient expertise for effective integration of cloud applications. The findings also revealed that participants perceived cloud applications as a valuable tool to improve many aspects of language education. Nonetheless, participants concentrated on integrating limited features of cloud applications. While the study revealed that there was no significant difference in participants\u27 expertise in integrating cloud applications based on the language they teach, it found that pre-service English teachers had significantly higher levels of positive perceptions and integration of cloud applications than pre-service Arabic teachers. Finally, a positive significant correlation was found between expertise, perceptions, and integration of cloud applications

Smart Banking Services and Their Impact on the Mental Image of Commercial Bank Customers in UAE

This study aimed to identify smart banking services represented by (Internet of things, data collection, data analysis, and security) and their impact on the mental image represented by (the cognitive dimension, the emotional dimension, the behavioral dimension) of commercial bank customers in the UAE. A convenience sample consisting of 384 customers of commercial banks in the Emirates was selected, and the descriptive analytical approach was used, and it reached many results, the most important of which was the existence of a statistically significant impact of Banking services represented by (Internet of things, data collection, data analysis and security) depend on the mental image represented combined, which means that bank customers have all and accurate information that contributed to the formation of a positive mental image and raised their confidence and satisfaction with these banks.In light of the results reached, the study recommended working on the development of smart banking services in all its dimensions and interest in providing bank customers in the UAE with more information about the Internet of Things, which contributes to improving the mental image of it, and given the importance of the subject in our current era, the study recommended the need to apply it to sectors other. Keywords: Smart banking services, mental image, bank customers, United Arab Emirate DOI: 10.7176/EJBM/15-17-09 Publication date:October 31st 202

Cloud Applications in Language Teaching

This study examined pre-service teachers\u27 expertise, perceptions and integration of cloud applications in teaching of Arabic and English. Questionnaires and semi-structured interviews were used as data collection methods. The findings of the study specified that pre-service teachers did not own sufficient expertise for effective integration of cloud applications. The findings also revealed that participants perceived cloud applications as a valuable tool to improve many aspects of language education. Nonetheless, participants concentrated on integrating limited features of cloud applications. While the study revealed that there was no significant difference in participants\u27 expertise in integrating cloud applications based on the language they teach, it found that pre-service English teachers had significantly higher levels of positive perceptions and integration of cloud applications than pre-service Arabic teachers. Finally, a positive significant correlation was found between expertise, perceptions, and integration of cloud applications

Best sum-throughput evaluation of cooperative downlink transmission nonorthogonal multiple access system

In cooperative simultaneous wireless information and power transfer (SWIPT) nonorthogonal multiple access (NOMA) downlink situations, the current research investigates the total throughput of users in center and edge of cell. We focus on creating ways to solve these problems because the fair transmission rate of users located in cell edge and outage performance are significant hurdles at NOMA schemes. To enhance the functionality of cell-edge users, we examine a two-user NOMA scheme whereby the cell-center user functions as a SWIPT relay using power splitting (PS) with a multiple-input single-output. We calculated the probability of an outage for both center and edge cell users, using closed-form approximation formulas and evaluate the system efficacy. The usability of cell edge users is maximized by downlink transmission NOMA (CDT-NOMA) employing a SWIPT relay that employs PS. The suggested approach calculates the ideal value of the PS coefficient to optimize the sum throughput. Compared to the noncooperative and single-input single-output NOMA systems, the best SWIPT-NOMA system provides the cell-edge user with a significant throughput gain. Applying SWIPT-based relaying transmission has no impact on the framework’s overall throughput

Behavioral intention to use mobile technology in language teaching: A qualitative analysis of a UAE case study

Copyright © 2020, IGI Global. Copying or distributing in print or electronic forms without written permission of IGI Global is prohibited. This study aimed to qualitatively investigate the factors that influence teachers\u27 behavioral intention to use mobile technology (BIU) for language teaching employing the original technology acceptance model (TAM) as a framework. Semi-structured interviews were conducted with 28 Arabic and English teachers. The study results revealed that there were several external variables influencing teachers\u27 behavioral intention to use mobile technology. It was also found that participants had mixed levels of perceived ease of use (PEOU), perceived usefulness (PU), and attitude toward use (ATU). Moreover, it was concluded that ATU had a direct impact on BIU and PU was the responsible factor for participants who had a mixed ATU

New microplanktonic biostratigraphy and depositional sequences across the Middle-Late Eocene and Oligocene boundaries in eastern Jordan

The first detailed calcareous nannofossil and planktonic foraminiferal biostratigraphic and integrated lithofacies analyses of the Eocene–Oligocene transition at the Qa’ Faydat ad Dahikiya area in the Eastern Desert of Jordan, on the border with Saudi Arabia, is presented. Three calcareous nannofossil zones namely: Discoaster saipanensis (NP17), Chiasmolithus oamaruensis (NP18) and Ericsonia subdisticha (NP21), and three planktonic foraminiferal zones: upper part of Truncorotaloides rohri (E13), Globigerinatheka semiinvoluta (E14) and Cassigerinella chipolensis/ Pseudohastigerina micra (O1) are identified. Calcareous nannofossil bioevents recorded in the present study show numerous discrepancies with the Standard biostratigraphic zonal schemes to detect the Middle/Upper Eocene boundary (e.g. the highest occurrences (HOs) of Chiasmolithus solitus, C. grandis, and lowest occurrences (LOs) of C. oamaruensis, Isthmolithus recurvus are not considered reliable markers for global correlation). The Middle/Upper Eocene boundary occurs in the current study above the extinctions of large muricate planktonic foraminifera (large Acarinina and Truncorotaloides spp.) which coincide within the equivalent calcareous nannofossil NP18 Zone. These microplanktonic bioevents seem to constitute more reliable markers for the base of the Upper Eocene in different provinces. The uppermost portion of the Middle Eocene is characterized by an observed drop in faunal content and, most likely, primarily denotes the effect of the major fall in eustatic sea level. A major unconformity (disconformity) marked by a mineralized hardground representing a lowstand is recorded in the present study at the Eocene–Oligocene transition that reveals an unexpected ca. 2.1 Myr duration, separating Eocene (NP18/E14 zones) from Oligocene (NP21/O1 zones). Furthermore, the microfossil turnover associated with a rapid decline of the microfossil assemblages shows a distinct drop in diversity and abundance towards the Eocene/Oligocene unconformity and is associated with a sharp lithological break marked, at the base, by a mineralized hardground representing a major sequence boundary. These bioevents, depositional sequences and the depositional hiatus correlate well with different parts of the Arabian and African plates, but the magnitude of the faunal break differs from place to place as a result of intraplate deformation during the regional Oligocene regression of Neo-Tethys on the northern Arabian Plate. The presence of the Lower Oligocene shallow-marine calcareous planktonic assemblages in the study area indicate that communication between the eastern and western provinces of the western Neo-Tethys region still existed at this time

General public knowledge, perceptions and practice towards pharmaceutical drug advertisements in the Western region of KSA

AbstractThis study aims to examine general public knowledge and behavior toward pharmaceutical advertisements in the Western part of KSA. A cross sectional convenience sampling technique was used in this study. A total of 1445 valid questionnaires were received and analyzed using SPSS version 16 at alpha value of 0.05. Majority of respondents were aware of different types of drugs to be advertised and drug advertisements should seek approval from the health authorities. Television and Internet showed the highest effect on consumers. Almost half of the participants preferred an advertised drug over non-advertised one. Most of the respondents indicated that the quality of frequently advertised drugs is not better than those prescribed by the doctors. Majority of participants had positive beliefs toward advertised drugs concerning their role in education and spreading of awareness among the public. Pharmaceutical advertisements harm the doctor–patient relationship as evidenced by one-third of the investigated sample. Moreover, majority of the participants mentioned that they would consult another doctor or even change the current doctor if he/she refused to prescribe an advertised medication. Results of this study could be used to develop awareness programs for the general public and try to enforce the regulations and policies to protect the general public and patients from the business oriented pharmaceutical companies and drug suppliers

Comparative study of the resolution efficiency of HPLC and HPTLC-densitometric methods for the analysis of mebeverine hydrochloride and chlordiazepoxide in their binary mixture

Accurate, rapid, and selective reversed phase HPLC and HPTLC-densitometric methods with UV detection have been developed and validated for simultaneous determination of a binary mixture of mebeverine hydrochloride (MVH) and chlordiazepoxide (CDZ) in their Co-formulation. For the HPLC method, ACE-126-2546 AQ C-18 column, (250×4.6 mm i.d., 5 μm particle size) in isocratic mode, with mobile phase containing 25 mM ammonium acetate buffer: acetonitrile in the ratio of (60:40, v:v), pH adjusted to 3±0.2 by using hydrochloric acid, the flow rate of 1.0 mL/min and detection was performed at 260 nm. The retention times were 7.23±0.01 and 3.85±0.01 min for MVH and CDZ, respectively. For the HPTLC-densitometric method, the separation was performed using stationary phase pre-coated silica gel 60F254 and mobile phase ethyl acetate: methanol (8:4, v:v) were used and scanned at 222 nm with Camag TLC scanner controlled by Wincats Software. The Rf values were 0.26±0.02 and 0.73±0.01 for MVH and CDZ, respectively. The linearity graphs for MVH and CDZ, respectively, were found to be linear over 1-50 μg/mL and 0.5-40.0 μg/mL with mean percentage recoveries 100.14±0.354 and 99.70±0.764 for HPLC method and 0.5-30.0 μg/band and 1-14 μg/band with mean percentage recoveries 100.29±0.665 and 99.68±0.987 for HPTLC-densitometric method. A comparative study of different analytical validation parameters such as accuracy, precision, specificity, robustness was conducted. The obtained results were statistically compared with those of the official methods; using student t-test, F-test, and one way ANOVA, showing no significant difference with respect to accuracy and precision