Diagrammatic rules are developed for simplifying two-loop QED diagrams with propagators in a constant self-dual background field. This diagrammatic analysis, using dimensional regularization, is used to explain how the fully renormalized two-loop Euler-Heisenberg effective Lagrangian for QED in a self-dual background field is naturally expressed in terms of one-loop diagrams. The connection bet...

the problem of pole assignment, also known as an eigenvalue assignment, in linear discrete-time periodic systems in discs was solved by a novel method which employs elementary similarity operations. the former methods tried to assign the points inside the unit circle while preserving the stability of the discrete time periodic system. nevertheless, now we can obtain the location of eigenvalues ...

We experimentally investigate the RF linewidth and timing jitter over a wide range of delay tuning in a self-mode-locked two-section quantum dash lasers emitting at ~ 1.55μm and operating at ~ 21 GHz repetition rate subject to single and dual optical feedback into gain section. Various feedback conditions are investigated and optimum levels determined for narrowest linewidth and reduced timing ...

Inverter voltage control is an important task in the operation of a DC/AC microgrid system. To improve the inverter voltage control dynamics, traditional approaches attempt to measure and feedforward the load current, which, however, needs remote measurement with communications in a microgrid system with distributed loads. In this paper, a load current observer (LCO) based control strategy, whi...

─ A novel loop-loaded printed dipole (LLPD) with a wideband balun structure is presented for aiming a dual-band antenna operation at 3.0/5.5 GHz bands. The proposed balun structure alone demonstrates VSWR<1.5 performance over a 3:1 bandwidth. As the loop elements placed on the antenna aperture provides dual-band operation with at least 15% impedance bandwidths, the wideband balun/feed allows fo...

conclusions according to the findings of the current study, both open-loop and closed-loop neuromuscular control mechanisms altered in patients with cai. methods it was a case-control study. twenty-two subjects with unilateral cai and 22 healthy subjects stood on a force plate and initiated gait with maximal velocity under 2 conditions: i) planned (initiated gait after hearing the “all set” sig...