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Previous models of the quantum regime of operation of the Free Electron Laser (QFEL) have performed an averaging and the application of periodic boundary conditions to the coupled Maxwell - Schrodinger equations over short, resonant…

Accelerator Physics · Physics 2018-02-14 M. S. Brown , J. R. Henderson , L. T. Campbell , B. W. J. McNeil

In this paper, we propose a shape optimization pipeline for propeller blades, applied to naval applications. The geometrical features of a blade are exploited to parametrize it, allowing to obtain deformed blades by perturbating their…

Optimization and Control · Mathematics 2024-01-17 Anna Ivagnes , Nicola Demo , Gianluigi Rozza

This work presents a machine learning approach to optimize the energy efficiency (EE) in a multi-cell wireless network. This optimization problem is non-convex and its global optimum is difficult to find. In the literature, either simple…

Signal Processing · Electrical Eng. & Systems 2023-12-18 Bile Peng , Karl-Ludwig Besser , Ramprasad Raghunath , Eduard A. Jorswieck

The data heterogeneity across devices and the limited communication resources, e.g., bandwidth and energy, are two of the main bottlenecks for wireless federated learning (FL). To tackle these challenges, we first devise a novel FL…

Machine Learning · Computer Science 2023-02-21 Zhixiong Chen , Wenqiang Yi , Arumugam Nallanathan , Geoffrey Ye Li

Laser-plasma accelerators offer a compact means of producing high-energy electron beams, but their performance is fundamentally limited by dephasing between the accelerated electrons and the plasma wave. To overcome this limitation, we…

This article presents new hexagonal and pentagonal PEM fuel cell models. The models have been optimized after achieving improved cell performance. The input parameters of the multi-objective optimization algorithm were pressure and…

Neural and Evolutionary Computing · Computer Science 2023-10-18 Ali Jabbary , Nader Pourmahmoud , Mir Ali Asghar Abdollahi , Marc A. Rosen

The equations describing the VFEL lasing in case of an electron beam moving either in a split of a diffraction grating or in a vacuum waveguide containing a diffraction grating (vacuum VFEL) have been obtained. The dispersion equation…

Accelerator Physics · Physics 2009-10-31 Vladimir G. Baryshevsky

This work puts forth a new optimal design formulation for planar elastic membranes. The goal is to minimize the membrane's compliance through choosing the material distribution described by a positive Radon measure. The deformation of the…

Optimization and Control · Mathematics 2023-08-03 Karol Bołbotowski

In this work we used Particle-In-Cell simulations to study the interaction of circularly polarised Alfv\'en waves with one dimensional plasma density inhomogeneities transverse to the uniform magnetic field (phase mixing) in collisionless…

Astrophysics · Physics 2007-05-23 David Tsiklauri , Jun-Ichi Sakai , Shinji Saito

It is reported that [Z. Huang et al., Phys. Rev. Lett. 109, 204801 (2012)], high-gain free-electron laser (FEL) can be generated by transverse-dispersed electron beams from laser-plasma accelerators (LPAs) using transverse-gradient…

Accelerator Physics · Physics 2016-08-11 G. Zhou , Y. Jiao , J. Wu , T. Zhang

Modulation constellation design is a core challenge in digital communications, especially under stringent demands on spectral efficiency, robustness, and energy consumption. Classical schemes like PSK and QAM, while analytically tractable,…

Signal Processing · Electrical Eng. & Systems 2026-01-22 Nipun Agarwal

This work presents the implementation, numerical examples and experimental convergence study of first- and second-order optimization methods applied to one-dimensional periodic gratings. Through boundary integral equations and shape…

Optimization and Control · Mathematics 2020-11-04 Rubén Aylwin , Gerardo Silva-Oelker , Carlos Jerez-Hanckes , Patrick Fay

We explore amplification and cross-Kerr nonlinearity by a three-level emitter (3LE) embedded in a waveguide and driven by two light beams. The coherent amplification and cross-Kerr nonlinearity were demonstrated in recent experiments,…

Quantum Physics · Physics 2020-05-08 Athul Vinu , Dibyendu Roy

There is a growing demand for X-ray Free-electron lasers (FELs) in various science fields, in particular for those with short pulses, larger photon fluxes and shorter wavelengths. The level of X-ray power and the pulse energy depend on the…

Accelerator Physics · Physics 2016-01-05 Yasmine Israeli , Jorge Vieira , Sven Reiche , Marco Pedrozzi , Patric Muggli

An efficient electro-optical modulation has been demonstrated here by using an edge plasmon mode specific for the hybrid plasmonic waveguide. Our approach addresses a major obstacle of the integrated microwave photonics caused by the…

Controlling waves by actively changing the material parameters of a medium enables the development of new acoustic and electrical devices. Modulating the material breaks classical properties like reciprocity and the conservation of energy,…

Numerical Analysis · Mathematics 2026-02-09 Jörg Nick

Reduced fluid models for collisionless plasmas including electron inertia and finite Larmor radius corrections are derived for scales ranging from the ion to the electron gyroradii. Based either on pressure balance or on the…

Plasma Physics · Physics 2018-01-23 T. Passot , P. L. Sulem , E. Tassi

An electron autoresonant acceleration by the rotating TM110 mode microwave field in an inhomogeneous magnetostatic field is studied. A set of differential equations describing the evolution of the phase shift between the electron angular…

Accelerator Physics · Physics 2023-05-22 Eduardo Orozco , Petr Tsygankov , Fredy Parada , Alejandro Hernández , Yerson Barragán

Nonlinear models are known to provide excellent performance in real-world applications that often operate in non-ideal conditions. However, such applications often require online processing to be performed with limited computational…

Machine Learning · Computer Science 2024-10-28 Danilo Comminiello , Alireza Nezamdoust , Simone Scardapane , Michele Scarpiniti , Amir Hussain , Aurelio Uncini

We consider the linear regression problem under semi-supervised settings wherein the available data typically consists of: (i) a small or moderate sized 'labeled' data, and (ii) a much larger sized 'unlabeled' data. Such data arises…

Methodology · Statistics 2018-07-02 Abhishek Chakrabortty , Tianxi Cai