Learning Adaptive Discriminative Correlation Filters via Temporal Consistency Preserving Spatial Feature Selection for Robust Visual Tracking

With efficient appearance learning models, Discriminative Correlation Filter (DCF) has been proven to be very successful in recent video object tracking benchmarks and competitions. However, the existing DCF paradigm suffers from two major issues, i.e., spatial boundary effect and temporal filter degradation. To mitigate these challenges, we propose a new DCF-based tracking method. The key innovations of the proposed method include adaptive spatial feature selection and temporal consistent constraints, with which the new tracker enables joint spatial-temporal filter learning in a lower dimensional discriminative manifold. More specifically, we apply structured spatial sparsity constraints to multi-channel filers. Consequently, the process of learning spatial filters can be approximated by the lasso regularisation. To encourage temporal consistency, the filter model is restricted to lie around its historical value and updated locally to preserve the global structure in the manifold. Last, a unified optimisation framework is proposed to jointly select temporal consistency preserving spatial features and learn discriminative filters with the augmented Lagrangian method. Qualitative and quantitative evaluations have been conducted on a number of well-known benchmarking datasets such as OTB2013, OTB50, OTB100, Temple-Colour, UAV123 and VOT2018. The experimental results demonstrate the superiority of the proposed method over the state-of-the-art approaches

Casimir effect with a helix torus boundary condition

We use the generalized Chowla-Selberg formula to consider the Casimir effect of a scalar field with a helix torus boundary condition in the flat ($D+1$)-dimensional spacetime. We obtain the exact results of the Casimir energy density and pressure for any $D$ for both massless and massive scalar fields. The numerical calculation indicates that once the topology of spacetime is fixed, the ratio of the sizes of the helix will be a decisive factor. There is a critical value $r_{crit}$ of the ratio $r$ of the lengths at which the pressure vanishes. The pressure changes from negative to positive as the ratio $r$ passes through $r_{crit}$ increasingly. In the massive case, we find the pressure tends to the result of massless field when the mass approaches zero. Furthermore, there is another critical ratio of the lengths $r_{crit}^{\prime}$ and the pressure is independent of the mass at $r=r_{crit}^{\prime}$ in the D=3 case.Comment: 11 pages, 3 figures, to be published in Mod. Phys. Lett.

Effect of mesenchymal stem cell transplantation on behavior and structural changes in myelin in experimental rat autoimmune encephalomyelitis

Purpose: To investigate the effect of bone marrow mesenchymal stem cell (BM-MSC) transplantation on behavior and structural changes in myelin of experimental autoimmune encephalomyelitis (EAE) in rats.Methods: Wistar rats were randomly assigned to normal control, EAE, placebo injection treatment, and MSCs treatment. EAE, placebo injection treatment and MSCs treatment groups were further divided into six groups, i.e., 1-day, 3-day, 7-day, 14-day, 21-day, and 28-day post-onset. Changes in the diseasestatus of the rats and structural changes in myelin at different time points were assessed with silver staining.Results: Behavioral changes peaked between 13 to 17 days post-immunization (71.90 % incidence), while disease symptoms peaked between 3 and 5 days after onset, were sustained for about 7 days, and then eased gradually thereafter. The highest therapeutic scores and the entire course of the disease in EAE and placebo treatment groups were not significantly different (p > 0.05). However, in MSC treatment group, these parameters were significantly lower than in the above two groups (p < 0.05). In EAE and placebo treatment groups, myelin sheath lesions were obvious from day 3 to 7 but on day 14, the number of myelin sheath fragments decreased significantly. Recovery at different time points was also better than those in EAE and placebo treatment groups.Conclusion: MSC transplantation shortens the course of EAE, and also reduces its severity. Thus, it has some prospects for use in the management of EAE.Keywords: Bone marrow mesenchymal stem cells, Autoimmune encephalomyelitis, Transplantation, Myeli

Estimation Method of Path-Selecting Proportion for Urban Rail Transit Based on AFC Data

With the successful application of automatic fare collection (AFC) system in urban rail transit (URT), the information of passengers’ travel time is recorded, which provides the possibility to analyze passengers’ path-selecting by AFC data. In this paper, the distribution characteristics of the components of travel time were analyzed, and an estimation method of path-selecting proportion was proposed. This method made use of single path ODs’ travel time data from AFC system to estimate the distribution parameters of the components of travel time, mainly including entry walking time (ewt), exit walking time (exwt), and transfer walking time (twt). Then, for multipath ODs, the distribution of each path’s travel time could be calculated under the condition of its components’ distributions known. After that, each path’s path-selecting proportion can be estimated. Finally, simulation experiments were designed to verify the estimation method, and the results show that the error rate is less than 2%. Compared with the traditional models of flow assignment, the estimation method can reduce the cost of artificial survey significantly and provide a new way to calculate the path-selecting proportion for URT