Multipath Routing over Wireless Mesh Networks

Master'sMASTER OF SCIENC

Intersite Coulomb repulsion driven quadrupole instability and magnetic ordering in the orbital frustrated Ba2_2MgReO6_6

We develop an unrestricted Hartree-Fock mean-field method including Coulomb repulsion U, V and spin-orbital coupling $\lambda$ self$-$consistently to investigate the mechanism of structural instability and magnetic ordering in Ba$_2$MgReO$_6$. A comprehensive quadrupole phase diagram versus U and V with $\lambda$=0.28eV is calculated. Our results demonstrate that, while U and $\lambda$ mainly lead to the onsite quadrupole $Q_{x^2-y^2}$ and $Q_{3z^2-r^2}$ with orbital frustration, the easy-plane anisotropy or the intersite Coulomb repulsion V can remove the frustration. Finally, the V$>$10meV would arrange $Q_{x^2-y^2}$ antiparallelly, accompanied with small parallel $Q_{3z^2-r^2}$, and stabilize Ba$_2$MgReO$_6$ into the body centered tetragonal structure. Such antiparallel $Q_{x^2-y^2}$ provides a new mechanism of Dzyaloshinskii-Moriya interaction, and gives rise to the canted antiferromagnetic (CAF) state along [110] axis. Moreover, sizable octupoles such as $O_{21}^{31}$, $O_{21}^{33}$, $O_{21}^{34}$ and $O_{21}^{36}$ are discovered for the first time in CAF states. Our study not only provides a comprehensive understanding of the nature and exotic properties in Ba$_2$MgReO$_6$, but also reveals some commonality of 5d compounds

Scheme of Overloaded Truck Control on a Rural Highway

A new working mode of overloaded traffic control for rural highways is presented, and a location-routing model is built to optimize the check base distribution and the control vehicles’ routing schemes. Then, for the location-routing model with a large set of location alternatives and an unknown settable number of check bases, a multiple ant colony optimization algorithm is designed to solve the model. Furthermore, actual data from Guiyang rural highways are used to perform a numerical analysis. The results indicate that the model can be used to obtain the optimal base location-vehicle routing scheme to verify the feasibility of the model and the algorithm. The model and algorithm can help managers to make decisions on locating the check bases and routing the control vehicles

Does widowhood affect cognitive function among Chinese older adults?

There is growing evidence from Western countries that widowhood may affect cognitive health in later life. However, little is known about whether widowhood isassociated with cognitive health in Eastern Asian countries such as China and what factors may explain the association between widowhood and cognitive health. Weadd to this line of research by investigating the effect of widowhood on 2-year change in cognitive function among Chinese adults ages 55 and older from 2011 to2013, using data from the China Health and Retirement Longitudinal Study. Cognitive function was measured by episodic memory and mental intactness (i.e.,attention and time orientation). Our results showed that Chinese older adults who were continually widowed at both waves had significantly lower episodic memoryscores at Wave 2 than their continually married counterparts, controlling for episodic memory at Wave 1, age, gender, education, and other sociodemographicvariables. This suggests that the continually widowed experienced greater decline in episodic memory than the continually married over the 2-year period. Afterfurther controlling for economic resources, health, and social engagement, the difference in memory decline between the continually widowed and the continuallymarried barely changed. The effect of widowhood on memory decline was similar for men and women. However, the continually widowed were not significantlydifferent from the continually married in the decline of mental intactness. In addition, newly widowed adults were not significantly different from the continuallymarried in the change of episodic memory and mental intactness. We conclude that staying widowed for 2 years or more may be an independent risk factor forepisodic memory decline in China. More research is needed to investigate the mediating and moderating mechanisms underlying the association between widowhoodand memory decline

Mildly Constrained Evaluation Policy for Offline Reinforcement Learning

Offline reinforcement learning (RL) methodologies enforce constraints on the policy to adhere closely to the behavior policy, thereby stabilizing value learning and mitigating the selection of out-of-distribution (OOD) actions during test time. Conventional approaches apply identical constraints for both value learning and test time inference. However, our findings indicate that the constraints suitable for value estimation may in fact be excessively restrictive for action selection during test time. To address this issue, we propose a Mildly Constrained Evaluation Policy (MCEP) for test time inference with a more constrained target policy for value estimation. Since the target policy has been adopted in various prior approaches, MCEP can be seamlessly integrated with them as a plug-in. We instantiate MCEP based on TD3-BC [Fujimoto and Gu, 2021] and AWAC [Nair et al., 2020] algorithms. The empirical results on MuJoCo locomotion tasks show that the MCEP significantly outperforms the target policy and achieves competitive results to state-of-the-art offline RL methods. The codes are open-sourced at https://github.com/egg-west/MCEP.git

Unbiased and Robust: External Attention-enhanced Graph Contrastive Learning for Cross-domain Sequential Recommendation

Cross-domain sequential recommenders (CSRs) are gaining considerable research attention as they can capture user sequential preference by leveraging side information from multiple domains. However, these works typically follow an ideal setup, i.e., different domains obey similar data distribution, which ignores the bias brought by asymmetric interaction densities (a.k.a. the inter-domain density bias). Besides, the frequently adopted mechanism (e.g., the self-attention network) in sequence encoder only focuses on the interactions within a local view, which overlooks the global correlations between different training batches. To this end, we propose an External Attention-enhanced Graph Contrastive Learning framework, namely EA-GCL. Specifically, to remove the impact of the inter-domain density bias, an auxiliary Self-Supervised Learning (SSL) task is attached to the traditional graph encoder under a multi-task learning manner. To robustly capture users' behavioral patterns, we develop an external attention-based sequence encoder that contains an MLP-based memory-sharing structure. Unlike the self-attention mechanism, such a structure can effectively alleviate the bias interference from the batch-based training scheme. Extensive experiments on two real-world datasets demonstrate that EA-GCL outperforms several state-of-the-art baselines on CSR tasks. The source codes and relevant datasets are available at https://github.com/HoupingY/EA-GCL.Comment: 9 pages, 4 figures, accepted by ICDM 2023 (workshop-GML4Rec