对先进多功能雷达系统行为的识别、推理与预测：综述与展望

多功能雷达（Multi-Function Radar, MFR）是先进体制雷达辐射源的典型代表,其能够在雷达时间线上对多个目标调度多个同时执行的任务,具有波束指向瞬时调度、工作模式灵活动态、信号调制复杂多变的特点。随着计算智能、认知理论、数字阵列、软件自定义及硬件可重构系统的不断发展,先进多功能雷达系统自由度和性能潜力不断提升,给现代电子侦察与对抗系统带来了巨大挑战。本文首先较为全面地给出了雷达系统行为的分类,依据雷达系统行为活动的内容与目的将雷达行为分为推理行为、决策行为和动作行为三类,并从雷达方和侦察方两个不同视角对上述三类行为进行了归类划分。然后围绕对先进MFR系统行为的感知识别难题,从侦察方视角对多功能雷达行为进行分析识别的侦察分析模型建模表征、雷达系统外显行为识别、内隐行为推理以及对未来行为预测等四方面对相关基础理论、实现技术的研究进行了全面梳理,并对未来研究面临的挑战和重点进行了分析,旨在为针对先进MFR系统行为相关的后续理论研究与技术发展提供有益参考。     

Resource constrained project scheduling problem with discounted earliness–tardiness penalties: Mathematical modeling and solving procedure

In this paper, we consider the resource-constrained project scheduling problem with a due date for each activity. The objective is to minimize the net present value of the earliness–tardiness penalty costs. The problem is first mathematically modeled. Then, two meta-heuristics, genetic algorithm and simulated annealing are proposed to solve this strongly NP-hard problem. Design of experiments and response surface methodology are employed to fine-tune the meta-heuristics’ parameters. Finally, a comprehensive computational experiment is described, performed on a set of instances and the results are analyzed and discussed.     

Homogeneous Penalizers and Constraints in Convex Image Restoration

Recently convex optimization models were successfully applied for solving various problems in image analysis and restoration. In this paper, we are interested in relations between convex constrained optimization problems of the form $\operatorname{argmin}\{ \varPhi(x) \mbox{ subject to } \varPsi(x) \le\tau\}$ and their penalized counterparts $\operatorname{argmin}\{\varPhi(x) + \lambda\varPsi(x)\}$ . We recall general results on the topic by the help of an epigraphical projection. Then we deal with the special setting Ψ:=∥L?∥ with L∈? ^m,n and Φ:=φ(H?), where H∈? ^n,n and φ:? ⁿ →?∪{+∞} meet certain requirements which are often fulfilled in image processing models. In this case we prove by incorporating the dual problems that there exists a bijective function such that the solutions of the constrained problem coincide with those of the penalized problem if and only if τ and λ are in the graph of this function. We illustrate the relation between τ and λ for various problems arising in image processing. In particular, we point out the relation to the Pareto frontier for joint sparsity problems. We demonstrate the performance of the constrained model in restoration tasks of images corrupted by Poisson noise with the I-divergence as data fitting term φ and in inpainting models with the constrained nuclear norm. Such models can be useful if we have a priori knowledge on the image rather than on the noise level.     

Position control of an electro-pneumatic system based on PWM technique and FLC

In this paper, modeling and PWM based control of an electro-pneumatic system, including the four 2–2 valves and a double acting cylinder are studied. Dynamic nonlinear behavior of the system, containing fast switching solenoid valves and a pneumatic cylinder, as well as electrical, magnetic, mechanical, and fluid subsystems are modeled. A DC–DC power converter is employed to improve solenoid valve performance and suppress system delay. Among different position control methods, a proportional integrator derivative (PID) controller and fuzzy logic controller (FLC) are evaluated. An experimental setup, using an AVR microcontroller is implemented. Simulation and experimental results verify the effectiveness of the proposed control strategies.     

Distributed QoE-aware channel assignment algorithms for IEEE 802.11 WLANs

Wireless Networks - One of the challenging problems with deployment of IEEE 802.11WLANs in the same hotspot is assignment of appropriate channels to the Access Points (APs). As the number of...     

Improvement of H2/CH4 Separation Performance of PES Hollow Fiber Membranes by Addition of MWCNTs into Polymeric Matrix

Carboxylated multiwalled carbon nanotubes (MWCNTs) were added to polyethersulfone hollow fiber membranes to improve their H₂/CH₄ separation properties. The addition of MWCNTs up to 1 wt% increased macrovoids formation in cross-section, while in 2 wt% loading, decreased due to increase in dope viscosity. The best gas separation performance for the mixed-matrix hollow fiber membranes was achieved at 1 wt% MWCNTs loading with hydrogen permeance of 69 GPU and H₂/CH₄ selectivity of 44.1 at 5 bar(g). Tensile test results showed that incorporation of MWCNTs into the polymeric matrix affected the mechanical properties of the fabricated membranes.