Dynamic Wireless QoS Analysis for Real-Time Control in URLLC

One of the major goals of ultra-reliable and low-latency communication (URLLC) is to enable real-time wireless control systems. However, it is challenging to use URLLC throughout the control process since a huge amount of wireless resource is needed to maintain the rigorous quality-of-service (QoS) in URLLC, i.e, ultra reliability and low latency. In this paper, our goal is to discuss that whether the extreme high QoS in URLLC leads to better control performance than low QoS during the control process. This is expected to provide a guideline on the usage of the URLLC throughout the control process dynamically. Specifically, we first investigate the relationship between the URLLC QoS and control performance. Then, we discuss the effect of different communication QoS on the control performance. Our results show that the rigorous QoS in URLLC and a low QoS can be used dynamically throughout the control process with high system performance

Proposal of Direct Search for Strongly Bound States of ppbar, npbar Systems with High Intensity and Collective pbar beam

In this letter, we discuss the possibility to look for the direct evidence of the existence of the ppbar and npbar bound states. Measurement of the single \gamma ray from the ppbar and npbar systems at rest can directly confirm whether the X(1860) and X(1835) are the resonances which are strongly coupled to ppbar. In addition to the neutral candidate, a charged resonance $X^-$ is also proposed to be searched for in npbar channel. We find that the data from the Crystal Barrel experiment at LEAR/CERN can be used to confirm the X(1835) observed by BES Collaboration. The possibility of measuring the $\gamma$ spectrum below 100 MeV at the new experiment with cold high intensity \pbar beam at GSI is discussed. These new techniques can be used to probe the structure of the X(1860) and X(1835) in the future.Comment: Accepted by Mod. Phys. Lett.

Quantum state transmission via a spin ladder as a robust data bus

We explore the physical mechanism to coherently transfer the quantum information of spin by connecting two spins to an isotropic antiferromagnetic spin ladder system as data bus. Due to a large spin gap existing in such a perfect medium, the effective Hamiltonian of the two connected spins can be archived as that of Heisenberg type, which possesses a ground state with maximal entanglement. We show that the effective coupling strength is inversely proportional to the distance of the two spins and thus the quantum information can be transferred between the two spins separated by a longer distance, i.e. the characteristic time of quantum state transferring linearly depends on the distance.Comment: 7 pages, 5 figures, 1 tabl

Realization of Zero-Refractive-Index Lens with Ultralow Spherical Aberration

Optical complex materials offer unprecedented opportunity to engineer fundamental band dispersion which enables novel optoelectronic functionality and devices. Exploration of photonic Dirac cone at the center of momentum space has inspired an exceptional characteristic of zero-index, which is similar to zero effective mass in fermionic Dirac systems. Such all-dielectric zero-index photonic crystals provide an in-plane mechanism such that the energy of the propagating waves can be well confined along the chip direction. A straightforward example is to achieve the anomalous focusing effect without longitudinal spherical aberration, when the size of zero-index lens is large enough. Here, we designed and fabricated a prototype of zero-refractive-index lens by comprising large-area silicon nanopillar array with plane-concave profile. Near-zero refractive index was quantitatively measured near 1.55 um through anomalous focusing effect, predictable by effective medium theory. The zero-index lens was also demonstrated to perform ultralow longitudinal spherical aberration. Such IC compatible device provides a new route to integrate all-silicon zero-index materials into optical communication, sensing, and modulation, and to study fundamental physics on the emergent fields of topological photonics and valley photonics.Comment: 14 pages, 4 figure

Diazido­bis­[4,4,5,5-tetra­methyl-2-(1,3-thia­zol-2-yl)-2-imidazoline-1-oxyl 3-oxide-κ2 N 1,O 3]nickel(II)

In the title compound, [Ni(N3)2(C10H14N3O2S)2], the NiII atom lies on an inversion center and adopts a distorted trans-NiO2N4 octa­hedral geometry, coordinated by two N,O-bidentate 4,4,5,5-tetra­methyl-2-(5-methyl­imidazol-4-yl)-2-imidazoline-1-oxyl 3-oxide nitronyl nitroxide radical ligands and two monodentate azide anions

H

This paper investigates the problem of H∞ filtering for class discrete-time Lipschitz nonlinear singular systems with measurement quantization. Assume that the system measurement output is quantized by a static, memoryless, and logarithmic quantizer before it is transmitted to the filter, while the quantizer errors can be treated as sector-bound uncertainties. The attention of this paper is focused on the design of a nonlinear quantized H∞ filter to mitigate quantization effects and ensure that the filtering error system is admissible (asymptotically stable, regular, and causal), while having a unique solution with a prescribed H∞ noise attenuation level. By introducing some slack variables and using the Lyapunov stability theory, some sufficient conditions for the existence of the nonlinear quantized H∞ filter are expressed in terms of linear matrix inequalities (LMIs). Finally, a numerical example is presented to demonstrate the effectiveness of the proposed quantized filter design method

Branching ratios and CP asymmetries of B→Kη(′)B \to K \eta^{(\prime)} decays in the pQCD approach

We calculate the branching ratios and CP violating asymmetries of the four B \to K \etap decays in the perturbative QCD (pQCD) factorization approach. Besides the full leading order contributions, the partial next-to-leading order (NLO) contributions from the QCD vertex corrections, the quark loops, and the chromo-magnetic penguins are also taken into account. The NLO pQCD predictions for the CP-averaged branching ratios are $Br(B^+ \to K^+ \eta) \approx 3.2 \times 10^{-6}$, Br(B^\pm \to K^\pm \etar) \approx 51.0 \times 10^{-6}, $Br(B^0 \to K^0 \eta) \approx 2.1 \times 10^{-6}$, and Br(B^0 \to K^0 \etar) \approx 50.3 \times 10^{-6}. The NLO contributions can provide a 70% enhancement to the LO Br(B \to K \etar), but a 30% reduction to the LO $Br(B \to K \eta)$, which play the key role in understanding the observed pattern of branching ratios. The NLO pQCD predictions for the CP-violating asymmetries, such as \acp^{dir} (K^0_S \etar) \sim 2.3% and \acp^{mix}(K^0_S \etar)\sim 63%, agree very well with currently available data. This means that the deviation \Delta S=\acp^{mix}(K^0_S \etar) - \sin{2\beta} in pQCD approach is also very small.Comment: 31 pages, 11 ps/eps figures, typos corrected. A little modificatio

Optimization Design for the Electron Emission System Using Improved Powell Method

The electron emission system, which may mostly decide the main properties of the whole electron optical system, is a crucial element for an electron gun. The design of the electron emission system is more important compared with other electron lenses in the electron gun. In this paper, an optimization design method for the electron emission system is presented by using an Improved Powell Method with linear search for the one dimensional search. The optimal structure parameters with a criterion of minimum objective function value for this system are provided. The computed results may show that this direct search optimization method is feasible and useful for the optimal design of the electron emission system as well as other electron optical systems