Some languages have very few NLP resources, while many of them are closely related to better-resourced languages. This paper explores how the similarity between the languages can be utilised by porting resources from better- to lesser-resourced languages. The paper introduces a way of building a representation shared across related languages by combining cross-lingual embedding methods with a lexical similarity measure which is based on the weighted Levenshtein distance. One of the outcomes of the experiments is a Panslavonic embedding space for nine Balto-Slavonic languages. The paper demonstrates that the resulting embedding space helps in such applications as morphological prediction, named-entity recognition and genre classification.

A theory of magnitudes involves criteria for their equivalence, comparison and addition. In this article we examine these aspects from an abstract viewpoint, by focusing on the so-called De Zolt’s postulate in the theory of equivalence of plane polygons (“If a polygon is divided into polygonal parts in any given way, then the union of all but one of these parts is not equivalent to the given polygon”). We formulate an abstract version of this postulate and derive it from some selected principles for magnitudes. We also formulate and derive an abstract version of Euclid’s Common Notion 5 (“The whole is greater than the part”), and analyze its logical relation to the former proposition. These results prove to be relevant for the clarification of some key conceptual aspects of Hilbert’s proof of De Zolt’s postulate, in his classical Foundations of Geometry (1899). Furthermore, our abstract treatment of this central proposition provides interesting insights for the development of a well-behaved theory of compatible magnitudes.

This article builds on Humberstone’s idea of defining models of propositional modal logic where total possible worlds are replaced by partial possibilities. We follow a suggestion of Humberstone by introducing possibility models for quantified modal logic. We show that a simple quantified modal logic is sound and complete for our semantics. Although Holliday showed that for many propositional modal logics, it is possible to give a completeness proof using a canonical model construction where every possibility consists of finitely many formulas, we show that this is impossible to do in the first-order case. However, one can still construct a canonical model where every possibility consists of a computable set of formulas and thus still of finitely much information.

This paper presents a comparative study on three types of slim coil structures used as a three-dimensional (3-D) receiver in a wireless power transfer system with a planar transmitter coil. The mutual coupling values and their variations between the receiver structures and the transmitter coil are compared under different distances and angular orientations with respect to the transmitter coil. The merits of performance are related to the consistency of the mutual coupling values under different orientations in a range of distances from the transmitter coil. The practical results show that slim 3-D receiver coil structures can be compatible with a planar transmitter coil with reasonably high-mutual coupling.

An internal wireless system (IWS) for satellites was proposed in a previous study to reduce the weight of satellites. It is a system that uses wireless communication modules to communicate between the satellite's subsystems. We proposed a complete IWS that employs microwave wireless power transmission technology, and we proposed a design of GHz band high efficiency rectifier based charge pump rectifiers with a class-f filter called class-f charge pump rectifiers. We theoretically compare the diode losses in a charge pump and single shunt rectifier, and experimentally verify the results. Apart from this, we consider that the class-f charge pump rectifiers will be used for a rectenna array. In order to know the direct current (DC) load change of class-f charge pump circuits is connected as a rectenna array, we measured the conversion efficiencies of a 2 by 2 rectenna array, connected in series and in parallel. The results of the experiment indicate that the optimum load of the rectifier changes to four times DC load when connected in series, and to 1/4 the DC load when connected in parallel.

Radiofrequency surface coils used as receivers in magnetic resonance imaging (MRI) rely on cables for communication and power from the MRI system. Complex surface coil arrays are being designed for improving acquisition speed and signal-to-noise ratio. This, in-turn makes the cables bulky, expensive, and the currents induced on cables by time-varying magnetic fields of the MRI system may cause patient harm. Though wireless power transfer (WPT) can eliminate cables and make surface coils safer, MRI poses a challenging electromagnetic environment for WPT antennas because the antennas made using long conductors interact with the static and dynamic fields of the MRI system. This paper analyses the electromagnetic compatibility of WPT antennas and reveals that commercially available antennas are not compatible with MRI systems, presenting a safety risk for patients. Even when the risk is minimized, the antennas couple with surface coils leading to misdiagnosis. This paper presents an approach to eliminate safety risks and minimize coupling using a filter named “floating filter.” A WPT antenna without a filter has a distortion of 27%, and floating filters reduce the distortion to 2.3%. Secondly, the floating filter does not affect the power transfer efficiency, and the transfer efficiency of 60% is measured with and without filters.

In this paper, possible coupling configurations of a four-plate capacitive power transfer system are studied by varying the combinations of its input and output ports. A voltage source is applied between two of the four plates, and a load is connected to the other two to form different circuit topologies. A mathematical model based on a 4 × 4 mutual capacitance matrix is established for equidistantly placed four identical metal plates. Based on the proposed model, four separate circuit topologies are identified and analysed in detail and described in a general form. The electric field distributions of the coupling configurations are simulated by ANSYS Maxwell. The theoretical modeling and analysis are then verified by a practical system, in which four aluminum plates of 300 mm × 300 mm are used and placed with a gap of 10 mm between adjacent plates. The experimental results show that the measured output voltage and power under the four coupling configurations are in good agreement with the theoretical results. It has found that the voltage gain is the highest when the two inner plates are connected to the source, and this coupling configuration also has the lowest leakage electric field.

Advances in technology have seen mobile robots becoming a viable solution to many global challenges. A key limitation for tetherless operation, however, is the energy density of batteries. Whilst significant research is being undertaken into new battery technologies, wireless power transfer may be an alternative solution. The majority of the available technologies are not targeted toward the medium power requirements of mobile robots; they are either for low powers (a few Watts) or very large powers (kW). This paper reviews existing wireless power transfer technologies and their applications on mobile robots. The challenges of using these technologies on mobile robots include delivering the power required, system efficiency, human safety, transmission medium, and distance, all of which are analyzed for robots operating in a hazardous environment. The limitations of current wireless power technologies to meet the challenges for mobile robots are discussed and scenarios which current wireless power technologies can be used on mobile robots are presented.

This paper presents an effective and time saving procedure for designing a three-coil resonant inductive wireless power transfer (WPT) link. The proposed approach aims at optimizing the power transfer efficiency of the link for given constraints imposed by the specific application of interest. The WPT link is described as a two-port network with equivalent lumped elements analytically expressed as function of the geometrical parameters. This allows obtaining a closed-form expression of the efficiency that can be maximized by acting on the geometrical parameters of the link by using a general purpose optimization algorithm. The proposed design procedure allows rapidly finding the desired optimal solution while minimizing the computational efforts. Referring to the case of an application constraining the dimensions of the receiver, analytical data are validated through full-wave simulations and measurements.

A novel, dual-band, voltage-multiplying (RF-DC) rectifier circuit with load-tuned stages resulting in a 50 Ω input-impedance and high RF-DC conversion in 2.4 and 5.8 GHz bands for wireless energy-harvesting is presented. Its novelty is in the use of optimal-length transmission lines on the load side of the 4 half-wave rectifying stages within the two-stage voltage multiplier topology. Doing so boosts the rectifier's output voltage due to an induced standing-wave peak at each diode's input, and gives the rectifier a 50 Ω input-impedance without an external-matching-network in the 2.4 GHz band. Comparisons with other rectifiers show the proposed design achieving a higher DC output and better immunity to changing output loads for similar input power levels and load conditions. The second novelty of this rectifier is a tuned secondary feed that connects the rectifier's input to its second stage to give dual-band performance in the 5.8 GHz band. By tuning this feed such that the second stage and first stage reactances cancel, return-loss resonance in the 5.8 GHz band is achieved in addition to 2.4 GHz. Simulations and measurements of the design show RF-DC sensitivity of −7.2 and −3.7 dBm for 1.8V DC output, and better than 10 dB return-loss, in 2.4 and 5.8 GHz bands without requiring an external-matching-network.