Trust, Security and Perceived Risk Models for Designing Internet Banking

This research assesses the behaviour patterns of existing bank customers towards Internet banking service in the UK (non-adopters and adopters), and their continuing usage or abandonment of service. The study also develops a theoretical model for trust, risks and Internet banking security, to achieve safety in the area of Internet banking services. Specifically, the majority of existing studies neglect patterns of post-adoption (continued use and abandonment of use) of Internet banking; focusing instead on either adoption or acceptance of internet banking (pre-adoption). The research in this thesis responds to this gap in the existing literature, offering a reassessment of the authentic use of Internet banking services in the UK. It does so by exploring the influence of trust, perceived risk, and security concerns, on customers’ behaviour and intention to use or not use Internet banking services. To address the study aims, it first develops conceptual frameworks. These encompass trust, security and perceived risk factors, and identification, and determine what influences consumers in their non-adoption, adoption, continued use, or abandonment of Internet banking. The study investigates customers located in Leicester city, and applies a quantitative research design, using a survey as the primary means of data collection. There were eight hundred and thirty eight valid copies (838) of the questionnaire, comprising a sample of 503 Internet banking users, 291 non-users of Internet banking and 44 abandoners of Internet banking. III A combination of simple regressions, correlation coefficients and frequencies (Categorical Variables), was used to analyse the data, by subjecting it to statistical analysis software SPSS. Initial statistical results displayed that 34.7% of the study sample were non-users of Internet banking, with Internet banking services abandonees being a minority. They represented just 5.30%, i.e. 44 customers from an overall study sample of 838. For them, trust, security and perceived risk were significant influences. Similarly, in adoption and continuity models, 60% of active users mentioned that trust has a low effect on their intentions for Internet banking adoption, while security and perceived risk had a very low influence on service adoption. On the other hand, the findings demonstrated that one-third of the users sampled mentioned other Internet banking adoption factors besides trust, namely: convenience, ease of use, saving time, ease of access, good monitoring and control of accounts, and speed when performing transactions. With regard to the continuity of usage, 87% of service users agree, or strongly agreed, about their future intentions regarding continuity. Reasons for continued use of Internet banking were trust, security and perceived risk. Additionally statistical analysis found weak relationships between perceived intentions and three factors. Further, the findings also highlighted that the relationships between demographic characteristics and customers’ trust, security and perceived risk were weak in three areas (Non-users, Abandoners and Users). One of the main contributions of this study is the development of a safety area model for Internet banking usage. The safety aspects identified were trust, security and low-risk degree between 53%, 51% and 9%, according to customers’ recommendations. IV This model will serve as a basis for future studies, to determine safety area in which to exercise Internet banking. However, the usefulness of this may vary from one environment to another and by time. Overall, the research contributes to knowledge and understanding of Internet banking patterns during two phases: pre-adoption and post-adoption of services (non-adoption, abandonment, adoption and continuity of use).Moreover, the research findings and insights will help bank executives, developers, academics, managers, and stakeholders, to formulate strategies and service frameworks to induce clients to accept services. Furthermore, maximising productivity and profitability through the creation of sustainable relationships in the long term with users will improve their satisfaction and retention. Bank administrators and decision makers should take advantage of the safety area model, and consider the views and recommendations of customers

Hybrid and modular multilevel converter designs for isolated HVDC–DC converters

Efficient medium and high-voltage dc-dc conversion is critical for future dc grids. This paper proposes a hybrid multilevel dc-ac converter structure that is used as the kernel of dc-dc conversion systems. Operation of the proposed dc-ac converter is suited to trapezoidal ac-voltage waveforms. Quantitative and qualitative analyses show that said trapezoidal operation reduces converter footprint, active and passive components' size, and on-state losses relative to conventional modular multilevel converters. The proposed converter is scalable to high voltages with controllable ac-voltage slope; implying tolerable dv/dt stresses on the converter transformer. Structural variations of the proposed converter with enhanced modularity and improved efficiency will be presented and discussed with regards to application in front-to-front isolated dc-dc conversion stages, and in light of said trapezoidal operation. Numerical results provide deeper insight of the presented converter designs with emphasis on system design aspects. Results obtained from a proof-of-concept 1-kW experimental test rig confirm the validity of simulation results, theoretical analyses, and simplified design equations presented in this paper. - 2013 IEEE.Scopu

Application of the cascaded multilevel inverter as a shunt active power filter

Abstract unavailable please refer to PD

A family of discontinuous PWM strategies for quasi Z-source nine-switch inverters

This paper proposes a new family of discontinuous PWM strategies to control the quasi-Z-source nine-switch inverters (qZS-NSI). The presented strategies provide buck and boost inversion capabilities, and suitable for common-frequency and different-frequency modes of operation. Accordingly, two different shoot-through (ST) approaches are introduced and compared. The first approach uses three-leg ST, while the second uses single-leg ST to reduce the number of switching commutations, therefore minimizing switching losses. Both approaches can be implemented using simple-boost (SB) and maximum boost (MB) control methods. The operating principles, performance criteria, and PWM modulator of each scheme are introduced. Compared to the conventional PWM technique for the same output voltage gains, the proposed schemes ensure continuous input current with minimum ripples, and the voltage stresses on the switching devices and capacitors could be reduced in the proposed MB control schemes. Moreover, the effective switching frequency of upper and lower switches of all schemes is fixed and could be reduced by 1/3 from the switching frequency of the conventional technique of the qZS-NSI, while only the single-leg ST schemes ensure minimum effective switching frequency of the middle switches. The proposed modulation strategies are digitally implemented and tested on the LAUNCHXL-F28379D DSP. The feasibility of the proposed modulation schemes is confirmed via simulation and experimental results, which show good agreement with the theoretical analysis. Moreover, the presented strategies can be applied to other types of Z-source NSIs.Scopu

Effects of Foreign Banks Presence on Emerging Economies: Evidence from Tanzania

Foreign banks presence has increased rapidly since 1990 where emerging economies lifted restrictions in their financial systems. Currently the ownership of foreign banks in many developing countries is more than 50%. Academically the positive effects of foreign banks participation are widely accepted in these emerging markets. However unlike studies of foreign investment in real sectors, little has been done to understand the negative effects from foreign banks to domestic banks and society in general. The importance of such understanding is crucial, especially after the break out of the global financial crisis and pandemic Covid 19 which raises certain concerns regarding the market – driven model of these emerging markets. The paper highlights this trend and survey the existing literature in order to explore the effects of foreign banks presence in emerging economies paying particular attention to Tanzania banking sector. It has been observed that; Competition and efficiency, stability and access to credits are among the effects that have been influenced by foreign banks participation. The descriptive results also revealed that foreign banks perform better in term of ROA and ROE than domestic banks in Tanzania during 2017 – 2021, but the performance of foreign banks is unstable and risky as compared to domestic banks. Keywords: Foreign banks presence, Domestic banks, Emerging Economies, Return on Asset, Return on Equity. DOI: 10.7176/RJFA/14-12-04 Publication date:June 30th 202

Hybrid multimodule DC-DC converters for ultrafast electric vehicle chargers

To increase the adoption of electric vehicles (EVs), significant efforts in terms of reducing the charging time are required. Consequently, ultrafast charging (UFC) stations require extensive investigation, particularly considering their higher power level requirements. Accordingly, this paper introduces a hybrid multimodule DC-DC converter-based dual-active bridge (DAB) topology for EV-UFC to achieve high-efficiency and high-power density. The hybrid concept is achieved through employing two different groups of multimodule converters. The first is designed to be in charge of a high fraction of the total required power, operating at a relatively low switching frequency, while the second is designed for a small fraction of the total power, operating at a relatively high switching frequency. To support the power converter controller design, a generalized small-signal model for the hybrid converter is studied. Also, cross feedback output current sharing (CFOCS) control for the hybrid input-series output-parallel (ISOP) converters is examined to ensure uniform power-sharing and ensure the desired fraction of power handled by each multimodule group. The control scheme for a hybrid eight-module ISOP converter of 200 kW is investigated using a reflex charging scheme. The power loss analysis of the hybrid converter is provided and compared to conventional multimodule DC-DC converters. It has been shown that the presented converter can achieve both high efficiency (99.6%) and high power density (10.3 kW/L), compromising between the two other conventional converters. Simulation results are provided using the MatLab/Simulink software to elucidate the presented concept considering parameter mismatches.Qatar Foundation; Qatar National Research FundScopu

Review on State-of-the-Art Unidirectional Non-Isolated Power Factor Correction Converters for Short-/Long-Distance Electric Vehicles

Electrification of the transportation sector has originated a worldwide demand towards green-based refueling infrastructure modernization. Global researches and efforts have been pondered to promote optimal Electric Vehicle (EV) charging stations. The EV power electronic systems can be classified into three main divisions: power charging station configuration (e.g., Level 1 (i.e., slow-speed charger), Level 2 (i.e., fast-speed charger), and Level 3 (i.e., ultra-fast speed charger)), the electric drive system, and the auxiliary EV loads. This paper emphasizes the recent development in Power Factor Correction (PFC) converters in the on-board charger system for short-distance EVs (e.g., e-bikes, e-trikes, e-rickshaw, and golf carts) and long-distance EVs (passenger e-cars, e-trucks, and e-buses). The EV battery voltage mainly ranges between 36 V and 900 V based on the EV application. The on-board battery charger consists of either a single-stage converter (a PFC converter that meets the demands of both the supply-side and the battery-side) or a two-stage converter (a PFC converter that meets the supply-side requirements and a DC-DC converter that meets the battery-side requirements). This paper focuses on the single-phase unidirectional non-isolated PFC converters for on-board battery chargers (i.e., Level 1 and Level 2 charging infrastructure). A comprehensive classification is provided for the PFC converters with two main categories: (1) the fundamental PFC topologies (i.e., Buck, Boost, Buck-Boost, SEPIC, C k, and Zeta converters) and (2) the modified PFC topologies (i.e., improved power quality PFC converters derived from the fundamental topologies). This paper provides a review of up-to-date publications for PFC converters in short-/long-distance EV applications.Qatar National Research FundScopu

Development of Modular DC-DC Converters for Low-Speed Electric Vehicles Fast Chargers

To increase the utilization of Low-Speed Electric Vehicles (LS-EVs), rapid recharging of the EV's battery pack turn out to be essential. This permits reduced charging times, greater vehicle utility, and broader adoption of LS-EVs. This paper presents a modular Input-Series Output-Parallel (ISOP) DC-DC converter for LS-EVs fast chargers. A generalized small-signal analysis applicable for any multimodule connection (Input-Series Input-Parallel Output-Series Output-Parallel (ISIP-OSOP) is introduced. The employed topology is a multimodule DC-DC converter based on Dual Active Bridge (DAB). Nonetheless, a single bridge is utilized at the primary side, and the modularity concept is applied to the high-frequency transformer and the second bridge where the connection of the modules is ISOP. In the presented system, 3-modules are employed where each module is rated at 1.5kWto achieve the desired power rating, which is 4.5kW. The charging process is achieved from a single-phase outlet. However, due to the high output current, a modular approach is required to avoid high losses. Uniform power-sharing is achieved through a direct output current sharing control, ensuring stability without the need for input voltage sharing loops, unlike the conventional ISOP converters. This is due to the fact that the proposed configuration uses only a single capacitor at the input side, avoiding the inherent instability problem caused by the output current sharing control. The controller is examined using a 3-module ISOP DC-DC converter, where the controlled current is following the reflex charging algorithm. Simulation results using the Matlab/Simulink platform are provided to elucidate the presented concept considering parameter mismatches, where the input voltage and the output current are equally shared among the three modules.Qatar Foundation;�Qatar National Research FundScopu

Quasi two-level PWM operation of a nine-arm modular multilevel converter for six-phase medium-voltage motor drives

This paper proposes a hybrid converter for medium-voltage six-phase machine drive systems that mixes the operation of a traditional two-level voltage-source inverter and the modular multilevel converter (MMC) to enable operation over a wide frequency range. Topologically, the proposed converter consists of nine arms resembling two sets of three-phase MMCs with three common arms, yielding a nine-arm MMC with a 25% reduction in the number of employed arms compared to a traditional dual three-phase MMC. The multilevel property of a standard MMC is emulated in the proposed converter, however on a two-level basis, resulting in a stepped two-level output voltage waveform. The proposed converter has a reduced footprint with advantages of small voltage steps, modular structure, and ease of scalability. Further, it is able to drive high-power six-phase machines within low operating frequencies at the rated torque. The operating principle of the converter is elaborated, and its modulation scheme is discussed. The features of the proposed converter are verified through simulations and experimentally