Inductive power transfer (IPT) systems are used in a wide range of applications. However, their practicality is reduced by the requirement of good alignment between the transmitter and receiver. One way to improve the...
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ISBN:
(数字)9798350349139
ISBN:
(纸本)9798350349146
Inductive power transfer (IPT) systems are used in a wide range of applications. However, their practicality is reduced by the requirement of good alignment between the transmitter and receiver. One way to improve the misalignment tolerance is to use coil arrays. This paper presents an optimization of PCB coil array for charging of a single coil receiver, both with ferrite. The optimization goal is to maximize the average efficiency while minimizing the coil array size and maintaining at least 15 W of transferred power at any position in the working area. Three array types are evaluated, all of which are based on a three-layer hexagonal pattern to provide homogenous magnetic field. Optimization employs the genetic algorithm NSGA-II with magnetic parameters for the coil array geometry evaluated using Maxwell Ansys. The optimized array operates with average efficiency of 84.4 % across all evaluated alignment positions.
The utilization of facial makeup is an important attribute in modern society as a means of self-expression, and as a method to feel more confident during social interactions. A makeover has become a necessity when att...
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This study introduces the system submitted to the SemEval 2022 Task 11: MultiCoNER (Multilingual Complex Named Entity Recognition) by the UC3M-PUCPR team. We proposed an ensemble of transformer-based models for entity...
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Superconducting motors are an enabling technology for future large scale electric transport, such as freight, aviation, and shipping. As cryogenics are essential for superconductivity, the power electronics used to dr...
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Safety is paramount in all swimming pools. The current systems expected to address the problem of ensuring safety at swimming pools have significant problems due to their technical aspects, such as underwater cameras ...
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We investigated the effect of copper ion concentration in zinc-copper dual-ion electrolytes to suppress dendrites and extend the cycle life of zinc ion capacitors. The devices were characterized in terms of changes in...
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ISBN:
(数字)9798331529468
ISBN:
(纸本)9798331529475
We investigated the effect of copper ion concentration in zinc-copper dual-ion electrolytes to suppress dendrites and extend the cycle life of zinc ion capacitors. The devices were characterized in terms of changes in microstructure and cycling stability. The nuclei size was decreased in the optimal copper ion concentration to promote lateral deposition and avoid vertical dendrites. The device exhibited stable cycling performance with a capacitance retention of 95% after 10,000 redox cycles, compared to the device with single zinc ion electrolyte which short circuited at around 1,250 redox cycles.
The Column Subset Selection (CSS) problem has been widely studied in dimensionality reduction and feature selection. The goal of the CSS problem is to output a submatrix S, consisting of k columns from an n × d i...
ISBN:
(纸本)9798331314385
The Column Subset Selection (CSS) problem has been widely studied in dimensionality reduction and feature selection. The goal of the CSS problem is to output a submatrix S, consisting of k columns from an n × d input matrix A that minimizes the residual error ||A – SS† A||2F where S† is the Moore-Penrose inverse matrix of S. Many previous approximation algorithms have non-linear running times in both n and d, while the existing linear-time algorithms have a relatively larger approximation ratios. Additionally, the local search algorithms in existing results for solving the CSS problem are heuristic. To achieve linear running time while maintaining better approximation using a local search strategy, we propose a local search-based approximation algorithm for the CSS problem with exactly k columns selected. A key challenge in achieving linear running time with the local search strategy is how to avoid exhaustive enumerations of candidate columns for constructing swap pairs in each local search step. To address this issue, we propose a two-step mixed sampling method that reduces the number of enumerations for swap pair construction from O(dk) to k in linear time. Although the two-step mixed sampling method reduces the search space of local search strategy, bounding the residual error after swaps is a non-trivial task. To estimate the changes in residual error after swaps, we propose a matched swap pair construction method to bound the approximation loss, ensuring a constant probability of loss reduction in each local search step. In expectation, these techniques enable us to obtain the local search algorithm for the CSS problem with theoretical guarantees, where a 53(k + 1)-approximate solution can be obtained in linear running time O(ndk4 log k). Empirical experiments show that our proposed algorithm achieves better quality and time compared to previous algorithms on both small and large datasets. Moreover, it is at least 10 times faster than state-of-the-art algorith
Quantum memory devices with high storage efficiency and bandwidth are essential elements for future quantum networks. Here, we report a storage efficiency greater than 28% in a Tm3+: YAG crystal in elevated temperatur...
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The increasing demand for high dynamic range (HDR), power efficiency, and high resolution has driven the adoption of single-exposure dual conversion gain (DCG) techniques. This paper proposes an adaptive split current...
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Quantum memory devices with high storage efficiency and bandwidth are essential elements for future quantum networks. Solid-state quantum memories can provide broadband storage, but they primarily suffer from low stor...
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