Scheduling and Power Control for Wireless Multicast Systems via Deep Reinforcement Learning

Multicasting in wireless systems is a natural way to exploit the redundancy in user requests in a content centric network. Power control and optimal scheduling can significantly improve the wireless multicast network’s performance under fading. However, the model-based approaches for power control and scheduling studied earlier are not scalable to large state spaces or changing system dynamics. In this paper, we use deep reinforcement learning, where we use function approximation of the Q-function via a deep neural network to obtain a power control policy that matches the optimal policy for a small network. We show that power control policy can be learned for reasonably large systems via this approach. Further, we use multi-timescale stochastic optimization to maintain the average power constraint. We demonstrate that a slight modification of the learning algorithm allows tracking of time varying system statistics. Finally, we extend the multi-time scale approach to simultaneously learn the optimal queuing strategy along with power control. We demonstrate the scalability, tracking and cross-layer optimization capabilities of our algorithms via simulations. The proposed multi-time scale approach can be used in general large state-space dynamical systems with multiple objectives and constraints, and may be of independent interest.     

GaAs中过渡金属深杂质能级的计算

本文采用41个原子的原子族模型来模拟晶体,用电荷-组态自洽(SCCC)的EHMO方法和在边界上用"类Ga"和"类As"原子来饱和悬挂键,计算了中性过渡金属原子Cr、Mn、Fe、Co、Ni在半导体GaAs中的深杂质态,所得杂质能级在带隙中的位置与实验结果相符。     

求解非均匀介质中电场反问题的一个新方法

以由R³中多层介质电场的部分数据出发,确定R³中某一区域的形状为例,抽象为最优控制问题,证明了该问题的解的存在性。给出了有限元方法和图论相结合的新算法,根据这个算法,进行多种数值实验,得到了L²下各种计算结果。     

An engineering formula on the calculation of oblique penetration by long-rod projectile

Based on the concept supposed in this paper that damage of a target is determined by momentum rather than by stress, an engineering .formula on the calculation of oblique penetration by long-rod projectile is established. The results calculated from this formula show good agreements with experimental data.     

自由拉氏方法进展

自由拉氏方法是模拟计算二维大变形可压缩流的一种新的尝试。它放弃了传统拉氏方法中网格间固定连接的约束,在计算中每个循环都要检验并且修改节点间的相邻关系,从而能够自动适应变形流动对网格的扭曲。此外我们对自由面和内界面也作了相应的处理。自由拉氏方法被用于流体或流体弹塑性流的计算并且给出了较为满意的结果。     

Primal–Dual–Infeasible Newton Approach for the Analytic Center Deep-Cutting Plane Method

The convergence and complexity of a primal–dual column generation and cutting plane algorithm from approximate analytic centers for solving convex feasibility problems defined by a deep cut separation oracle is studied. The primal–dual–infeasible Newton method is used to generate a primal–dual updating direction. The number of recentering steps is O(1) for cuts as deep as half way to the deepest cut, where the deepest cut is tangent to the primal–dual variant of Dikin's ellipsoid.     

基于图像深度预测的景深视频分类算法

景深视频因高清、美观广受大众喜爱。然而,要从海量视频中检出此类视频十分困难。已有较多研究基于景深图像成像原理,开展景深像素分割算法研究,但难以直接应用于实际视频分类场景。本文针对景深视频类型,设计了可预测视频类型的深度网络。根据景深成像原理,各语义物体之间相对相机的景深深度存在一定的逻辑关系。为此提出以图像深度为指导,利用深度预测模块预测图像的景深深度信息,将其合并后输入至分类网络进行训练检测,以降低景深视频误检率,提升网络模型的性能。此外,针对现实需求中该领域有标数据较少,而不同数据集分布会降低性能的问题,设计了迭代式景深视频数据集收集方法,以较低的劳动成本快速收集所需要的视频数据,具有一定的实际应用价值。本文算法在快手线上的景深视频数据集中识别准确率达85.7%。     

RF electric field penetration and power deposition into nonequilibrium planar-type inductively coupled plasmas

The RF electric field penetration and the power deposition into planar-type inductively coupled plasmas in low-pressure discharges have been studied by means of a self-consistent model which consists of Maxwell equations combined with the kinetic equation of electrons. The Maxwell equations are solved based on the expansion of the Fourier--Bessel series for determining the RF electric field. Numerical results show the influence of a non-Maxwellian electron energy distribution on the RF electric field penetration and the power deposition for different coil currents. Moreover, the two-dimensional spatial profiles of RF electric field and power density are also shown for different numbers of RF coil turns.     

疏松砂岩油藏深部稳砂体系配方设计与应用

针对油藏充填砂的治理,研制了一种新型的防膨抑砂剂NTW-1。室内性能评价表明,防膨抑砂剂具有防膨和抑砂能力,其效果分别优于目前常用的其它抑砂剂或粘土稳定剂的平均水平10.5%和65.6%,同时现场使用简便、成本较低。根据油藏出砂机理,提出了“深部稳砂”新观点,以合成的防膨抑砂剂NTW-1为基础,研究了“深部稳砂”新体系配方,现场应用表明,与常规措施相比,该体系增强了充填砂与骨架砂间的结合力,阻止了深部充填砂的运移,缩小了出砂空间,防砂成功率和有效期分别提高了8.8%和37.3%,单井增油平均提高了46.2%。