There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality.

Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

I and i

A topical review of numerical and experimental studies of supercontinuum generation in photonic crystal fiber is presented over the full range of experimentally reported parameters, from the femtosecond to the continuous-wave regime. Results from numerical simulations are used to discuss the temporal and spectral characteristics of the supercontinuum, and to interpret the physics of the underlying spectral broadening processes. Particular attention is given to the case of supercontinuum generation seeded by femtosecond pulses in the anomalous group velocity dispersion regime of photonic crystal fiber, where the processes of soliton fission, stimulated Raman scattering, and dispersive wave generation are reviewed in detail. The corresponding intensity and phase stability properties of the supercontinuum spectra generated under different conditions are also discussed.

Supercontinuum generation in photonic crystal fiber

This Review explains the concept of dissipative solitons and their application to high-energy mode-locked fibre laser cavities. Dynamics and effects such as dissipative soliton ‘explosions’ and ‘rain’ are summarized, and an outlook of the field is also provided.

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Dissipative solitons for mode-locked lasers

DC–DC converters with voltage boost capability are widely used in a large number of power conversion applications, from fraction-of-volt to tens of thousands of volts at power levels from milliwatts to megawatts. The literature has reported on various voltage-boosting techniques, in which fundamental energy storing elements (inductors and capacitors) and/or transformers in conjunction with switch(es) and diode(s) are utilized in the circuit. These techniques include switched capacitor (charge pump), voltage multiplier, switched inductor/voltage lift, magnetic coupling, and multistage/-level, and each has its own merits and demerits depending on application, in terms of cost, complexity, power density, reliability, and efficiency. To meet the growing demand for such applications, new power converter topologies that use the above voltage-boosting techniques, as well as some active and passive components, are continuously being proposed. The permutations and combinations of the various voltage-boosting techniques with additional components in a circuit allow for numerous new topologies and configurations, which are often confusing and difficult to follow. Therefore, to present a clear picture on the general law and framework of the development of next-generation step-up dc–dc converters, this paper aims to comprehensively review and classify various step-up dc–dc converters based on their characteristics and voltage-boosting techniques. In addition, the advantages and disadvantages of these voltage-boosting techniques and associated converters are discussed in detail. Finally, broad applications of dc–dc converters are presented and summarized with comparative study of different voltage-boosting techniques.

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Step-Up DC–DC Converters: A Comprehensive Review of Voltage-Boosting Techniques, Topologies, and Applications

The Internet of Things (IoT) is the next era of communication. Using the IoT, physical objects can be empowered to create, receive, and exchange data in a seamless manner. Various IoT applications focus on automating different tasks and are trying to empower the inanimate physical objects to act without any human intervention. The existing and upcoming IoT applications are highly promising to increase the level of comfort, efficiency, and automation for the users. To be able to implement such a world in an ever-growing fashion requires high security, privacy, authentication, and recovery from attacks. In this regard, it is imperative to make the required changes in the architecture of the IoT applications for achieving end-to-end secure IoT environments. In this paper, a detailed review of the security-related challenges and sources of threat in the IoT applications is presented. After discussing the security issues, various emerging and existing technologies focused on achieving a high degree of trust in the IoT applications are discussed. Four different technologies, blockchain, fog computing, edge computing, and machine learning, to increase the level of security in IoT are discussed.

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A Survey on IoT Security: Application Areas, Security Threats, and Solution Architectures

We present our experiences in the design and delivery of a foundation unit for first-year students in electronic engineering and related specialisations. The aim of the unit was to provide engineering students with foundation skills for their subsequent engineering studies, with an emphasis on communication skills, working in groups, and design. The unit development process commenced as part of a project to introduce engineering academics to problem-based learning, with the development of the foundation unit set as a workshop project. The project had limited success in the latter context, however the resulting foundation unit proved very popular with most students.

Development of a New Foundation Unit in Engineering

Temperature tuning of an optically-pumped distributed-feedback laser formed by a thin film of MEH-PPV semiconducting polymer is reported. The tuning coefficient about 625 nm was approximately -0.4 nm/K, mainly attributable to the thermooptic coefficient of the MEH-PPV.

Temperature tuning of a semiconducting-polymer DFB laser

A method of reducing electromagnetic interference in a power converter, the impedance source based power converter including a series of switches controlling a series of active, zero and shoot through states of the voltage converter, by means of switch control threshold levels, the method including the step of: (a) driving the switches with an anharmonic modulation of the switch control threshold levels.

Modulation method and apparatus to reduce emi in a power converter

Generation of highly chirped pulses in a diode-pumped optical fiber laser

This paper reviews the various computer tools that have been reported for modeling the impacts of electrical vehicles on the power distribution grid. Forty four computer tools have been identified and summarised to facilitate selection of the most appropriate tools for specific tasks. Typical applications of the tools include vehicle design, analysis, control, grid integration and impact, market scheduling, and energy management. No single tool addresses all requirements, however sufficient information is provided to enable researchers to choose the appropriate combination of tools to meet specific research objectives.

Graham Town

Papers

Development of a New Foundation Unit in Engineering

Temperature tuning of a semiconducting-polymer DFB laser

Modulation method and apparatus to reduce emi in a power converter

Generation of highly chirped pulses in a diode-pumped optical fiber laser

A review of computer tools for analyzing the impact of electric vehicles on power distribution