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The purpose of this paper is to model and analyze energy transfer through near‐field resonant coupling for high power light‐emitting diode (HPLED) illumination, with the intention to increase the appreciation and use of the coupled mode theory (CMT) other than the usual equivalent circuit method.

The CMT is extensively used to analyze the wireless energy transfer system because of its generality, simplicity, accuracy and intuitive understanding of near‐field resonant energy coupling mechanism.

The CMT forms a general way to model and analyze the non‐radiative magnetic resonant coupling systems. It is suitable not only for low frequency coupling but also for high frequency (of million‐Hertz) in which the circuit parameters are not easily obtained. Optimal coupling condition corresponding to the maximum power transfer is identified based on the CMT, and the multiple limit cycle phenomenon caused by the nonlinear nature of the HPLED is also described on the CMT model.

This paper takes advantages of CMT, i.e. generality, simplicity, accuracy and intuitive understanding to analyze the near‐field resonant energy coupling system. Key characteristics of the systems are explored based on the CMT, not the usual equivalent circuit method. The influence of nonlinear nature of the high power LED on energy transfer is also investigated. This work seeks a more general way than conventional equivalent circuit method to model and analyze the resonant magnetic system and the results obtained could facilitate better understanding of the resonant magnetic coupling mechanism and optimal design of the near‐field energy transfer system.

This paper aims to suggest and research a revolutionary method‐transfer of electricity in outer Space with distance of hundreds of millions kilometers by ultra‐cool plasma cables.

Methods of the plasma and electricity physic are used for research.

Theory of plasma cable transferring is offered, developed and its possibilities researched.

This method uses a high voltage electricity and plasma source (accelerator).

Offers conclusions from the research of a revolutionary new idea‐transferring electric energy in the hard vacuum of outer space wirelessly, using a plasma power cord as an electric cable (wire). He computed the macroprojects: transference of hundreds kilowatts of energy to Earth's Space Station, transferring energy to the Moon or back, transferring energy to a spaceship at distance 100 million of kilometers, the transfer energy to Mars when one is located at opposite side of the distant Sun, transfer colossal energy from one of Earth's continents to another continent (for example, between Europe – USA) wirelessly – using Earth's ionosphere as cable, using Earth as gigantic storage of electric energy, using the plasma ring as huge MagSail for moving of spaceships.

The paper provides information on a revolutionary method for the transfer of electricity in outer space.

This paper aims to develop mathematical models of variously compensated wireless energy transfer (WET) systems. Attention is primarily paid to the derivation of the most important energy transfer characteristics such as efficiency and amount of transferred power. This paper discusses the main advantages and disadvantages of various compensation techniques to show their possible application areas. On the basis of these results, a designer will be able to quickly identify which compensation type suites as the best solution to fulfill a given system’s requirements.

First, the current state in the field of mathematical modeling of WET systems is introduced. Next, the non-resonant magnetic-coupled circuit together with four most common resonant magnetic-coupled circuits is analyzed. The equivalent circuit models using loop currents methodology is applied to the analyses. The proposed methodology is experimentally verified by the laboratory measurement of selected circuit topology. The main contribution of the proposed methodology lies in its quick applicability on more complicated or extended systems while keeping a relatively good match with the real system’s behavior.

The authors have presented the usage of a simple and accurate methodology for investigating variously compensated WET systems. Electrical engineers who require effective and powerful tools for the identification of basic WET systems properties will find this methodology to be of extensive help.

The analyses consider only the sinusoidal type of supply voltage; so, it is valid mainly for the close range of the resonant state. Nonlinearities cannot be taken into account.

This research may be applied in the field of WET systems.

Research in the area of power electronic systems, which provides a clear and straightforward procedure for WET system identification, will be helpful to most practical technicians who are not well versed in areas of physical-based phenomena.

To simplify the circuit design and control complexity of the magnetic coupling resonant wireless charging system, the radio energy transmission constant current and constant voltage charging is realized.

The purpose of this study is to simplify the circuit design and control complexity of the magnetic coupling resonance wireless charging system, in order to achieve constant current and constant voltage charging for wireless energy transmission. First, the principle of LCC/S-S compensation structure is analyzed, and the equivalent mathematical model is established; then, the system characteristics under constant current and constant voltage mode are analyzed, and the design method of system parameters is given; finally, a simulation and experimental system is built to verify the correctness and feasibility of the theoretical analysis.

The results show that the proposed hybrid topology can achieve a constant current output of 2 A and a constant voltage output of 30 V under variable load conditions, and effectively suppress the current distortion problem under light load conditions. The waveform distortion rate of the inverter current is reduced from 33.97% to 10.45%.

By changing the high-order impedance characteristics of the compensation structure, the distortion of the current waveform under light load is suppressed, and the overall stability and efficiency of the system are improved.

Wireless power transfer (WPT) is deemed as an emerging technology with exciting applications, like wireless charging devices, and electric vehicles, whereas metamaterials exhibit exceptional properties. For every WPT system that occupies coupled magnetic resonances, it is also mandatory to involve resonators. The purpose of this paper is to introduce a new interdigitated split-ring resonator (I-SRR) as the basic part of a WPT system, pursuing advanced levels of efficiency.

A novel WPT system, which exploits I-SRRs as its elementary blocks, is comprehensively examined. The analysis investigates the distance between the modules, the distance between transmitting and receiving components as well as the geometrical features of the structure. Several numerical data derived via the finite element method unveil the merits of the featured configuration.

The proposed arrangement reveals a noteworthy enhancement of the power delivered to the load and a promising tuning of the operational frequency via the interdigitated topology. Several parametric studies clarify the principal characteristics of the proposed setup, facilitating the design of high-end systems. In particular, the distance between the resonators and the port loops affect the matching of the input and output ports, allowing optimisation of power efficiency, while the length of the I-SRR gap can determine the operational frequency.

Development of a WPT system, which utilises I-SRRs as its key elements. Incorporation of metamaterials into WPT technology. Efficiency enhancement of WPT systems and alternative design via geometrical modifications. The necessity of lumped elements to implement the WPT resonators is eliminated by utilising split-ring resonators components, enabling compactness in several implementations.

This paper aims to present new analytical expressions for the mutual inductance and forces between non-coaxial co-planar circular thin-wall air coils.

The expressions are based on an integration method found in the literature, so far used only to describe mutual inductances. It is new to apply this method as a starting point to get the forces between non-coaxial co-planar rings and coils. The approach is further extended to include non-coaxial co-planar thin-wall cylindrical coils.

This new method enables interaction modelling between coils by solving integrals numerically, covering fully, partially and non-overlapping coils in a single form. The expressions are verified by comparing the results with alternatives methods.

The forces and mutual inductances of non-coaxial co-planar circular coils are obtained with analytical expressions, fitted well for optimization studies. The study is limited to coils in free air.

A typical application is the interaction between coils in a wireless energy transfer system (as applied for battery loading for mobile phones and automotive). The expressions can be used to also predict the forces between two non-coaxial disk or ring magnets as used in magnetic levitation systems.

Maxwell described the coupling between two coaxial co-planar rings, and steadily more and more equations describing the interaction between circular coils became available in the past decades. The target of this study is to obtain compact equations for non-coaxial co-planar circular coils. This is realized with the combination of existing literature and mathematical modelling tools.

The purpose of this paper is to describe a semi-analytical modeling technique to predict eddy currents in three-dimensional (3D) conducting structures with finite dimensions. Using the developed method, power losses and parasitic forces that result from eddy current distributions can be computed.

In conducting regions, the Fourier-based solutions are developed to include a spatially dependent conductivity in the expressions of electromagnetic quantities. To validate the method, it is applied to an electromagnetic configuration and the results are compared to finite element results.

The method shows good agreement with the finite element method for a large range of frequencies. The convergence of the presented model is analyzed.

Because of the Fourier series basis of the solution, the results depend on the considered number of harmonics. When conducting structures are small with respect to the spatial period, the number of harmonics has to be relatively large.

Because of the general form of the solutions, the technique can be applied to a wide range of electromagnetic configurations to predict, e.g. eddy current losses in magnets or wireless energy transfer systems. By adaptation of the conductivity function in conducting regions, eddy current distributions in structures containing holes or slit patterns can be obtained.

With the presented technique, eddy currents in conducting structures of finite dimensions can be modeled. The semi-analytical model is for a relatively low number of harmonics computationally faster than 3D finite element methods. The method has been validated and shown to be computationally accurate.

Shrinking population can have significant negative impacts on the social and economic fabric of a city. This paper aims to understand different urban transportation policies to respond to population decline in shrinking cities by examining two case studies of urban interventions in mid-size cities in Japan.

The paper analyzes the implementation of sustainable mobility strategies in the urban transport sector in the Japanese cities of Toyama and Kanazawa, which risk having their populations significantly reduced in the next decades. The analysis is based on case study research that uses the data and information collected through desk and field research. Interviews with local actors, as well as published policy and academic documents on the case studies provided critical data and information to analyze the case studies.

Both cities have tried to make urban mobility more sustainable via different strategies. Toyama used more structural changes, called the “sticks and dumplings” approach, having land use incentives and the Light Rail Transit reinforced by bus routes as the backbone of its strategy. Kanazawa relied on a city center revitalization plan to densify residential use in the city center.

More structural interventions are necessary to change the declining of shrinking cities, mitigating some of the negative effects. City administrations need to have clear policy priorities and should not allocate their limited resources to competing policy agendas.

The study is unique as it is one of the first efforts to analyze urban transportation interventions in shrinking cities in Japan.

This article aims to provide details of recent robotic exoskeleton developments and applications.

Following an introduction, this article first considers some of the technological issues associated with an exoskeleton design. It then discusses military developments, industrial load-carrying applications and uses in healthcare. Progress in thought-controlled exoskeletons is discussed briefly, and finally, concluding comments are drawn.

This article shows that, while military interests continue, the dominant application is to restore or enhance mobility to individuals suffering from disabilities or injuries. An emerging use is to increase the strength and endurance of industrial workers. The majority are lower-limb devices, although some full-body exoskeletons have been developed, and most rely on battery-powered electric motors to create motion. Reflecting the anticipated growth in applications, exoskeletons are now available from, or under development by, a growing number of commercial organisations.

This provides an insight into the latest developments in robotic exoskeletons and their applications.

The purpose of this paper is to gain a better understanding on how metasurfaces behave, in terms of currents in each unit cell. A better knowledge of their behavior could lead to an ad-hoc design for specific applications.

The methodology used is both theoretical and numerical; it is based on circuit theory and on an optimization procedure.

The results show that when the knowledge of the current in each unit cell of a metasurface is needed, the most common approximations currently used are often not accurate. Furthermore, a procedure for the termination of a metasurface, with application-driven goals, is given.

This paper investigates the distribution of the currents in a 2D metamaterial realized with magnetically coupled resonant coils. Different models for the analysis of these structures are illustrated, and the effects of the approximations they introduce on the current values are shown and discussed. Furthermore, proper terminations of the resonators on the boundaries have been investigated by implementing a numerical optimization procedure with the purpose of achieving a uniform distribution of the resonator currents. The results show that the behavior of a metasurface (in terms of currents in each single resonator) depends on different properties; as a consequence, their design is not a trivial task and is dependent on the specific applications they are designed for. A design strategy, with lumped impedance termination, is here proposed.