The nature of ZbZ_b states from a combined analysis of Υ(5S)→hb(mP)π+π−\Upsilon(5S)\rightarrow h_b(mP) \pi^+ \pi^- and Υ(5S)→B(∗)Bˉ(∗)π\Upsilon(5S)\rightarrow B^{(\ast)}\bar B^{(\ast)}\pi

With a combined analysis of data on $\Upsilon(5S)\rightarrow h_b(1P,2P)\pi^+\pi^-$ and $\Upsilon(5S)\rightarrow B^{(\ast)}\bar B^{(\ast)}\pi$ in an effective field theory approach, we determine resonance parameters of $Z_b$ states in two scenarios. In one scenario we assume that $Z_b$ states are pure molecular states, while in the other one we assume that $Z_b$ states contain compact components. We find that the present data favor that there should be some compact components inside $Z_b^{(\prime)}$ associated with the molecular components. By fitting the invariant mass spectra of $\Upsilon(5S)\rightarrow h_b(1P,2P)\pi^+\pi^-$ and $\Upsilon(5S)\rightarrow B^{(\ast)}\bar B^{\ast}\pi$, we determine that the probability of finding the compact components in $Z_b$ states may be as large as about $40\%$.Comment: Discussions added, version published in EPJ

The exponential cost optimality for finite horizon semi-Markov decision processes

summary:This paper considers an exponential cost optimality problem for finite horizon semi-Markov decision processes (SMDPs). The objective is to calculate an optimal policy with minimal exponential costs over the full set of policies in a finite horizon. First, under the standard regular and compact-continuity conditions, we establish the optimality equation, prove that the value function is the unique solution of the optimality equation and the existence of an optimal policy by using the minimum nonnegative solution approach. Second, we establish a new value iteration algorithm to calculate both the value function and the $\epsilon$-optimal policy. Finally, we give a computable machine maintenance system to illustrate the convergence of the algorithm

A Clustering-Anonymity Approach for Trajectory Data Publishing Considering both Distance and Direction

Trajectory data contains rich spatio-temporal information of moving objects. Directly publishing it for mining and analysis will result in severe privacy disclosure problems. Most existing clustering-anonymity methods cluster trajectories according to either distance- or direction-based similarities, leading to a high information loss. To bridge this gap, in this paper, we present a clustering-anonymity approach considering both these two types of similarities. As trajectories may not be synchronized, we first design a trajectory synchronization algorithm to synchronize them. Then, two similarity metrics between trajectories are quantitatively defined, followed by a comprehensive one. Furthermore, a clustering-anonymity algorithm for trajectory data publishing with privacy-preserving is proposed. It groups trajectories into clusters according to the comprehensive similarity metric. These clusters are finally anonymized. Experimental results show that our algorithm is effective in preserving privacy with low information loss

catena-Poly[[(1,10-phenanthroline)lead(II)]bis­(μ-5-chloro-2-hy­droxy­benzoato)]

In the title polymer, [Pb(C7H4ClO3)2(C12H8N2)]n, the Pb(II) ion displays a distorted pseudo-octa­hedral coordination geometry. The metal center is coordinated by six O atoms from four 5-chloro­salicylate ligands and two N atoms from a chelating phenanthroline ligand. The polymeric structure is built up from bridging carboxyl­ate O atoms, forming chains along [100]. The crystal structure is stabilized by π–π inter­actions between the 1,10-phenanthroline and 5-chloro­salicylate ligands, the shortest centroid–centroid separation between neighbouring aromatic rings being 3.652 (1) Å

Three-dimensional ionospheric tomography algebraic reconstruction technique

An improved algebraic reconstruction technique (IART) is presented for the tomographic reconstruction of ionospheric electron density (IED). This method applies the total electron content (TEC) measurements to invert the spatial distribution of the IED from a set of apriori IED distributions. In this new method, a data-driven adjustment of the relaxation parameter is performed to improve the computation efficiency and image quality of the classical algebraic reconstruction technique (ART). In addition, the new algorithm is also combined with ionospheric space discretization technique to simplify the inversion of IED, and it applies CHAMP occultation data to improve the vertical resolution. A numerical simulation experiment is carried out to validate the reliability of the new method. It is then applied to the inversion of IED from real GPS data. Inverted results show that the IART algorithm has better accuracy and efficiency than the conventional ART algorithm. The reliability of the IART algorithm is also validated by ionosonde data recorded at Wuhan station

Poly[diaqua­(μ3-succinato)cadmium(II)]

The title compound, [Cd(C4H4O4)(H2O)2]n, has been synthesized under hydro­thermal conditions. The asymmetric unit consists of one Cd2+ cation, one succinate anion and two aqua ligands. The Cd atoms present a distorted penta­gonal bipyramidal coordination and are bridged into layers parallel to (201) by succinate ligands