综合孔径辐射计中二级相关算法的设计与实现

为了解决传统微波遥感辐射计使用FPGA实现多通道数字相关器时资源消耗量过大的问题,本文提出了一种二级相关实现方法.二级相关算法将相关算法分成前后两级,并利用门时钟生成单元使系统保持流型工作状态.前级相关器由基本逻辑资源构成,完成固定短点数的相关处理;多个前级相关器分为一组,分时启动并复用后级长点数相关器.二级相关算法能显著解决微波遥感辐射计中多通道数字相关器资源消耗量巨大的问题,提高数字相关器所容纳的相关通道数,同时优化了FPGA布局布线性能,能提高系统性能并降低成本.     

工业过程生态生命周期评价的生态累积耗模型

生态生命周期评价(Eco-LCA)作为常规生命周期评价的拓展,提供了一种对工业过程生态影响及可持续性分析评价的方法.但目前Eco-LCA中尚缺失生态累积耗(ECEC)指标的完整模型.本文探讨了工业过程中自然资源消耗、社会经济投入和环境污染危害三种主要影响因素.通过构建囊括资源、经济、环境三要素的工业过程生态累积耗模型,完善了Eco-LCA方法应用于工业过程可持续分析的理论框架.最后,以此生态累积耗模型对中国原油生产进行了示例性分析讨论.     

Optimized joint cell planning and BS on/off switching for LTE networks

Energy is becoming a main concern nowadays due to the increasing demands on natural energy resources. Base stations (BSs) consume up to 80% of the total energy expenditure in a cellular network. In this paper, we propose and evaluate a green radio network planning approach by jointly optimizing the number of active BSs and the BS on/off switching patterns based on the changing traffic conditions in the network in an effort to reduce the total energy consumption of the BSs. The problem is formulated as an integer optimization problem, which proves to be NP‐complete, and thus it can be efficiently solved for small to medium network sizes. For large network sizes, we propose a heuristic solution with close to optimal performance because the optimal solution becomes computationally complex. Planning is performed based on two approaches: a reactive and a proactive approach. In the proactive approach, planning will be performed starting with the lowest traffic demand until reaching the highest traffic demand, whereas in the reactive approach, the reverse way is considered. Performance results are presented for various case studies and are complemented by testing the proposed approaches using commercial radio network planning tools. Results demonstrate considerable energy savings reaching up to 40% through dynamic adaptation of the number of simultaneously active BSs. Copyright © 2015 John Wiley & Sons, Ltd.     

Game of energy consumption balancing in heterogeneous sensor networks

In a multi‐hop sensor network, sensors largely rely on other nodes as a traffic relay to communicate with targets that are not reachable by one hop. Depending on the topology and position of nodes, some sensors receive more relaying traffic and lose their energy faster. Such imbalanced energy consumption may lead to server problems like network partitioning. In this paper, we study the problem of energy consumption balancing (ECB) in heterogeneous sensor networks by assuming general any‐to‐any traffic pattern. We consider both factors of transmission power and forwarding load in measuring energy consumption. To find a solution, we formulate the problem as a strategic network formation game with a new utility function. We show that this game is guaranteed to converge to strongly connected topologies which have better ECB and bounded inefficiency. We propose a localized algorithm in which every node knows only about its k‐hop neighbourhood. Through simulations on uniform and clustered networks with various densities, we show that the performance of our algorithm is comparable with global and centralized algorithms. Copyright © 2015 John Wiley & Sons, Ltd.     

A note on optimal investment–consumption–insurance in a Lévy market

In Shen and Wei (2014) an optimal investment, consumption and life insurance purchase problem for a wage earner with Brownian information has been investigated. This paper discusses the same problem but extend their results to a geometric Itô–Lévy jump process. Our modelling framework is very general as it allows random parameters which are unbounded and involves some jumps. It also covers parameters which are both Markovian and non-Markovian functionals. Unlike in Shen and Wei (2014) who considered a diffusion framework, ours solves the problem using a novel approach, which combines the Hamilton–Jacobi–Bellman (HJB) and a backward stochastic differential equation (BSDE) in a Lévy market setup. We illustrate our results by two examples.     

CIR利率模型中基于对数效用的投资组合最优化问题

本文研究了CIR 利率模型中基于对数效用的最优长期投资问题和无限时间域上的最优折算消费问题. 通过求解相关的动态规划方程, 获得了这两个最优化问题的最优策略及值函数的明确表现形式.     

基于BP网络巡航段油耗估计及影响结构分析

针对影响因素众多、各因素之间耦合关系复杂,相对油耗呈显著非线性问题,提出了一种基于BP网络的神经元组合线性方法。该方法实现了复杂非线性关系的逼近,并利用MIV算法进行影响因素结构分析,以及各因素微小变化对巡航段油耗的贡献。实验结果对比表明：该方法建立的模型预测精度较高,泛化能力较强,对实际飞行中航线飞行油耗估计以及影响因素评估具有参考价值。     

畜牧养殖用料量检测系统设计与实现

针对国内目前畜牧养殖业饲料使用量大,但大吨位称重传感器价格较高、而且安装不方便、精度不高的问题,设计开发了一种畜牧养殖用料量检测系统;该系统多点采集用料量高度值,通过高度值间接计算出用料量体积,针对料塔内饲料密度不均衡性,通过三维拟合法估算不同高度对应的饲料密度系数,使用体积乘以密度计算出实时用料量;经实际验证,该系统检测用料量误差在3%以内。     

Controlling a chaotic resonator by means of dynamic track control

Josephson junction oscillators can generate chaotic signals with a wide frequency spectrum. An improved scheme of Lyapunov functions is proposed to control chaotic resonators of this type and forces them to converge to an arbitrary selected target signal. A changeable gain coefficient is introduced into the Lyapunov function, and the controllers are designed analytically. The controllers operate automatically when the output series are deviated from the target orbit synchronously. A resistive‐capacitive‐inductive‐shunted Josephson junction in chaotic parameter region is investigated in our studies, and power consumption is estimated from the dimensionless model. It is found that the power consumption of controller is dependent on the amplitude and/or angular frequency of the external target signal to be tracked. For example, larger power costs are observed when the target signal is in larger amplitude and/or angular frequency. The numerical results are consistent with the analytical discussion. © 2014 Wiley Periodicals, Inc. Complexity 21: 370–378, 2015