Analytical Studies on a Modified Nagel-Schreckenberg Model with the Fukui-Ishibashi Acceleration Rule

We propose and study a one-dimensional traffic flow cellular automaton model of high-speed vehicles with the Fukui-Ishibashi-type (FI) acceleration rule for all cars, and the Nagel-Schreckenberg-type (NS) stochastic delay mechanism. By using the car-oriented mean field theory, we obtain analytically the fundamental diagrams of the average speed and vehicle flux depending on the vehicle density and stochastic delay probability. Our theoretical results, which may contribute to the exact analytical theory of the NS model, are in excellent agreement with numerical simulations.Comment: 3 pages previous; now 4 pages 2 eps figure

Understanding the 0++0^{++} and 2++2^{++} charmonium(-like) states near 3.9 GeV

We propose that the $X(3915)$ observed in the $J/\psi\,\omega$ channel is the same state as the $\chi_{c2}(3930)$, and the $X(3960)$, observed in the $D_s^+D_s^-$ channel, is an $S$-wave $D_s^+ D_s^-$ hadronic molecule. In addition, the $J^{PC}=0^{++}$ {component in the $B^+\to D^+D^-K^+$} assigned to the $X(3915)$ in the current {\it Review of Particle Physics} has the same origin as the $X(3960)$, which has a mass around 3.94~GeV. To check the proposal, the available data in the $D\bar D$ and $D_s^+ D_s^-$ channels from both $B$ decays and $\gamma\gamma$ fusion reaction are analyzed considering both the $D\bar D$-$D_s\bar D_s$-$D^*\bar D^*$-$D_s^*\bar D_s^*$ coupled channels with $0^{++}$ and a $2^{++}$ state introduced additionally. It is found that all the data in different processes can be simultaneously well reproduced, and the coupled-channel dynamics produce four hidden-charm scalar molecular states with masses around 3.73, 3.94, 3.99 and 4.23~GeV, respectively. The results may deepen our understanding of the spectrum of charmonia as well as of the interactions between charmed hadrons.Comment: 15 pages, 6 figures, 2 tables, to apear in Sci. Bul

Multi-object tracking with robust object regression and association

Tracking-by-regression is a new paradigm for online Multi-Object Tracking (MOT). It unifies detection and tracking into a single network by associating targets through regression, significantly reducing the complexity of data association. However, owing to noisy features from nearby occlusions and distractors, the regression is vulnerable and unaware of the inter-object occlusions and intra-class distractors. Thus the regressed bounding boxes can be wrongly suppressed or easily drift. Meanwhile, the commonly used bounding box-based post-processing is unable to remedy false negatives and false assignments caused by regression. To address these challenges, we present to leverage regression tubes as input for the regression-based tracker, which provides spatial–temporal information to enhance the tracking performance. Specially, we propose a novel tube re-localization strategy that obtains robust regressions and recovers missed targets. A tube-based NMS (T-NMS) strategy to manage the regressions at the tube level is also proposed, including a tube IoU (T-IoU) scheme for measuring positional relation and tube re-scoring (T-RS) to evaluate the quality of candidate tubes. Finally, a tube re-assignment strategy is further employed for robust cost measurement and to revise false assignments using motion cues. We evaluate our method on benchmarks, including MOT16, MOT17, and MOT20. The results show that our method can significantly improve the baseline, mitigate the challenges of the regression-based tracker, and achieve very competitive tracking performance.</p

Posterior urethral hamartoma with hypospadias in a child: a case report and literature review

BackgroundHamartoma is a mass formed by the proliferation and disorder of two or more kinds of cells inherent in normal organs or anatomical parts, which can occur in any part of the body. The most common hamartoma are kidney hamartoma, spleen hamartoma, liver hamartoma, and lung hamartoma. Urethral hamartoma is extremely rare in clinical practice.Case reportCombined with literature review, the diagnosis and treatment process of a child with posterior urethral hamartoma and hypospadias in our hospital were analyzed. The patient was cured after surgical treatment, the lesion was completely removed, the appearance was satisfactory, and there was no recurrence, urethral stricture, urethral fistula, and other complications. The pathological results of this case support the histological diagnosis of hamartoma, which provides reference for the clinical diagnosis and treatment of congenital malformation and tumor of urogenital in children.ConclusionWhen a child has posterior urethral hamartoma, the symptoms may not be very typical, and it is often combined with urethral malformation. Therefore, it is necessary to perform careful physical examination combined with pathological examination to be able to make an accurate diagnosis. Under normal circumstances, the prognosis of urethral hamartoma is good. However, more cases are needed to be observed for verification, and a long-term effective follow-up after surgery is needed

Entanglement dynamics of two-qubit system in different types of noisy channels

In this paper, we study entanglement dynamics of a two-qubit extended Werner-like state locally interacting with independent noisy channels, i.e., amplitude damping, phase damping and depolarizing channels. We show that the purity of initial entangled state has direct impacts on the entanglement robustness in each noisy channel. That is, if the initial entangled state is prepared in mixed instead of pure form, the state may exhibit entanglement sudden death (ESD) and/or be decreased for the critical probability at which the entanglement disappear.Comment: 11 pages, 6 figure

The controlled teleportation of an arbitrary two-atom entangled state in driven cavity QED

In this paper, we propose a scheme for the controlled teleportation of an arbitrary two-atom entangled state $|\phi>_{12}=a|gg>_{12}+b|ge>_{12}+c|eg>_{12}+d|ee>_{12}$ in driven cavity QED. An arbitrary two-atom entangled state can be teleported perfectly with the help of the cooperation of the third side by constructing a three-atom GHZ entangled state as the controlled channel. This scheme does not involve apparent (or direct) Bell-state measurement and is insensitive to the cavity decay and the thermal field. The probability of the success in our scheme is 1.0.Comment: 10 page