A comparative study of glitch-free true single-phase clocked D flip-flop circuits at low supply voltage

This paper investigates the characteristics and performances of several true single-phase clocked (TSPC) D flip-flops (D-FFs) at low supply voltage. We propose a new glitch-free D-FF for low-voltage operation. Since the dynamic power consumption in CMOS is proportional to V_dd², decreasing the supply voltage yields a large reduction in power consumption. The main design objectives for these circuits are glitch-free operation and low power consumption at low supply voltage. The proposed D-FF circuit has been compared with previously known circuits and has been shown to provide superior performance. All circuits in this paper have been simulated using HSPICE with a 0.4-μm CMOS technology at a 2-V supply voltage. An analysis of a serial pipeline multiplier design establishes the superiority of the proposed circuit in that application.     

The Dynamics of a Prey-dependent Consumption Model Concerning Integrated Pest Management

A mathematical model for the dynamics of a prey-dependent consumption model concerning integrated pest management is proposed and analyzed. We show that there exists a globally stable pesteradication periodic solution when the impulsive period is less than some critical values. Furthermore, the conditions for the permanence of the system are given. By using bifurcation theory, we show the existence of a nontrival periodic solution if the pest-eradication periodic solution loses its stability. When the unique positive periodic solution loses its stability, numerical simulation shows there is a characteristic sequence of bifurcations, leading to a chaotic dynamics, which implies that dynamical behaviors of prey-dependent consumption concerning integrated pest management are very complex, including period-doubling cascades, chaotic bands with periodic windows, crises, symmetry-breaking bifurcations and supertransients.     

有随机现金流时投资优化问题的显式解

利用随机动态规划方法,研究了有随机现金流Yt的最优投资问题.假设Yt满足dYt=α(Xt)dt+β(Xt)dW2,其中Xt为投资者的总财富.不同于经典Merton模型的是,在新的目标函数max f,c P(τb＜τα| X0=x0)下,给出了最优投资策略的显式解.     

基于无线传感器网络能耗系统的研究

节能已经成为无线传感器网络研究的核心部分。该文研究了无线传感器网络拓扑结构的邻近节点数对网络能耗的影响,主要采用动态电压调节技术(DVS)来降低无线传感器网络中节点的能耗。动态电压调节主要通过减少门等效电容、供电电压以及降低转换因子、时钟频率来达到降低动态能耗的目的,其中,降低供电电压节能效果最佳。与其他方法相比,动态电压调节降低能耗更加明显、效率更高。通过在CC2430节点芯片上测试验证,通过改变其分频比,得出了功耗和频率的近似线性关系。     

Experimental and predictive study on the performance and energy consumption characteristics for the regeneration of activated alumina assisted by ultrasound

Activated alumina used in dehumidification should be regenerated at more than 110 °C temperature, resulting in excessive energy consumption. Comparative experiments were conducted to study the feasibility and performance of ultrasonic assisted regeneration so as to lower the regeneration temperature and raise the efficiency. The mean regeneration speed, regeneration degree, and enhanced rate were used to evaluate the contribution of ultrasound in regeneration. The effective moisture diffusivity and desorption apparent activation energy were calculated by theoretical models, revealed the enhanced mechanism caused by ultrasound. Also, we proposed some specific indexes such as unit energy consumption and energy-saving ratio to assess the energy-saving characteristics of this process. The unit energy consumption was predicted by artificial neural network (ANN), and the recovered moisture adsorption of activated alumina was measured by the dynamic adsorption test. Our analysis illustrates that the introduction of power ultrasound in the process of regeneration can reduce the unit energy consumption and improve the recovered moisture adsorption, the unit energy consumption was decreased by 68.69% and the recovered moisture adsorption was improved by 16.7% under 180 W power ultrasound compared with non-ultrasonic assisted regeneration at 70 °C when initial moisture adsorption was 30%. Meanwhile, an optimal regeneration condition around the turning point could be obtained according to the predictive results of ANN, which can minimize the unit energy consumption. Moreover, it was found that a larger specific surface area of activated alumina induced by ultrasound contributed to a better recovered moisture adsorption.     

基于随机网络演算的无线通信系统能耗分析

提出了一个在一定传输时延约束下能量消耗最少的最优化问题,并建立了相应的无线通信系统模型,然后利用随机网络演算理论研究时延约束、传输速率与能量消耗之间的关系,最后得出了最优化问题的最优解。     

传输设备节能减排潜力分析

对在当前全业务及LTE建设的环境下移动某省公司传输设备的耗电情况进行了估算及趋势分析,指出随着传输耗电日益增加的形势下传输设备的节能减排将是未来节能的重点领域之一。同时对不同厂家设备耗电进行比较,相互的偏离程度为33%220%。不同厂商设备能耗差别较大暗示了现有设备存在较大的节能空间。现阶段传输设备节能减排迫切性强,同时具备较大的节能空间,急需引起产业界重视及进行节能技术研究。     

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。