Short-term load forecasting using bayesian neural networks learned by Hybrid Monte Carlo algorithm

This paper presents a short term load forecasting model based on Bayesian neural network (shorted as BNN) learned by the Hybrid Monte Carlo (shorted as HMC) algorithm. The weight vector parameter of the Bayesian neural network is a multi-dimensional random variable. In learning process, the Bayesian neural network is considered as a special Hamiltonian dynamical system, and the weights vector as the system position variable. The HMC algorithm is used to learn the weight vector parameter with respect to Normal prior distribution and Cauchy prior distribution, respectively. The Bayesian neural networks learned by Laplace algorithm and HMC algorithm and the artificial neural network (ANN) learned by the BP algorithm were used to forecast the hourly load of 25 days of April (Spring), August (Summer), October (Autumn) and January (Winter), respectively. The roots mean squared error (RMSE) and the mean absolute percent errors (MAPE) were used to measured the forecasting performance. The experimental result shows that the BNNs learned by HMC algorithm have far better performance than the BNN learned by Laplace algorithm and the neural network learned BP algorithm and the BNN learned by HMC has powerful generalizing capability, it can welly solve the overfitting problem.     

Robust H ∞ control of uncertain nonlinear switched systems using constructive method

This paper focuses on the problem of robust H _?? control of nonlinear switched systems with parameter uncertainty via the multiple Lyapunov functions (MLFs) approach. The uncertain parameters are assumed to be in a known compact set and are allowed to enter the system nonlinearly. Based on the explicit construction of Lyapunov functions, which avoids solving the Hamilton-Jacobi-Isaacs (HJI) inequalities, sufficient conditions for the solvability of the robust H _?? control problem of cascade nonlinear switched systems are derived under some switching signal. Then, the result is extended to solve the robust H _?? control problem of nonlinear switched systems in strict feedback form. Finally, the effectiveness of the proposed results is illustrated through a simulation example.     

FD—140型高灵敏测氡仪及其应用

FD—140型高灵敏测氡仪用于测量氡的浓度,测氡灵敏度可达15mBq/m~3 min。该仪器可用于普查与勘探铀矿床,也可用于找石油、煤、金、地下水和地震预报以及地质构造调查等方面。     

项目管理在IT企业中的推广与应用

现阶段传统的管理模式还是一些中小型IT企业的主要管理方式。这种方式导致很多中小型IT企业发展的新旧项目成功率都很小。所以,在当前情况下,要大大加强项目管理的涉及度,使之进入中小IT企业。从而,提高中小企业的核心竞争力。那么什么IT企业,何为项目管理,项目管理在IT企业中的推广应用,以及二者之间的相互关系就是我们研究的重要课题。     

Damping forced oscillations in power system via interline power flow controller with additional repetitive control

With the continuous expansion of power systems and the application of power electronic equipment, forced oscillation has become one of the key problems in terms of system safety and stability. In this paper, an interline power flow controller (IPFC) is used as a power suppression carrier and its mechanism is analyzed using the linearized state-space method to improve the system damping ratio. It is shown that although the IPFC can suppress forced oscillation with well-designed parameters, its capability of improving the system damping ratio is limited. Thus, combined with the repetitive control method, an additional repetitive controller (ARC) is proposed to further dampen the forced power oscillation. The ARC control scheme is characterized by outstanding tracking performance to a system steady reference value, and the main IPFC controller with the ARC can provide higher damping, and further reduce the amplitude of oscillations to zero compared with a supplementary damping controller (SDC). Simulation results show that the IPFC with an ARC can not only greatly reduce the oscillation amplitude, but also actively output the compensation power according to the reference value of the ARC tracking system.     

表面工程技术在导弹武器装备维修中的应用

本文主要介绍铝/F_(46),协合涂层新技术、复合电刷镀Ni—PTFE新工艺、DJB—823电接触保护剂及三防电子器件绝缘清漆在二炮导弹武器装备维修中的应用。     

挤压变形对Mg95Zn4.3Y0.7合金组织和性能的影响

研究了在250℃、不同挤压比下挤压变形对Mg95 Zn4.3 Y0.7合金组织及性能的影响。结果表明，Mg95 Zn4.3 Y0.7经过挤压变形后，合金中晶界处的共晶相破碎，弥散分布至晶粒内部，并且晶粒显著细化。同时，随着挤压比的增大，晶粒细化程度增加，合金的力学性能单调增加。当挤压比为16时，合金晶粒尺寸为5-8μm，抗拉强度为288.9MPa，显微硬度HV值为117.8。     

一种就地化保护装置硬件架构设计

随着智能电网的不断深入发展,对于继电保护装置的要求也越来越高,继电保护装置的小型化、就地化已成为一种发展趋势.基于这种需求,介绍了一种适用于就地化保护装置的硬件架构设计方案.该方案基于ZYNQ核心系统,简化了常用的CPU+FPGA核心系统,硬件架构由下往上整体呈现三层式、功能分立模块化,不同模块间基于CAN总线来通信,具有易调试、小型化、可靠性高及模块化等特点.     

Facile Fabrication of Povidone Iodine-Embedded Polytetrafluoroethylene Superhydrophobic Films with Improved Antiadhesive and Bactericidal Properties in Bacterial Environments

It remains a challenge to maintain the antiadhesion properties of superhydrophobic films after exposure to bacterial environments. In this work, superhydrophobic bactericidal polymer films via the simple incorporation of polyvinylpyrrolidone-iodine (PVP-I) or iodine into polytetrafluoroethylene (PTFE) are fabricated to improve their antiadhesive and antibacterial capability. Superhydrophobic iodine-embedded films, polytetrafluoroethylene/polyvinylpyrrolidone-iodine and polytetrafluoroethylene-iodine (PTFE/PVP-I and PTFE-I), show excellent antiadhesive and bactericidal performances even post exposure to bacterial solutions as compared to iodine-free counterparts by controlling the release of iodine. Especially, superhydrophobic PTFE/PVP-I films display a more sustained iodine release profile and significant antibacterial properties against gram-positive (S. aureus, methicillin-resistant S. aureus (MRSA)) and gram-negative (E. coli) bacteria. Such a facile combination of antiseptic agents and superhydrophobic surface could be widely used for antiseptic biomedical applications.     

气-电纺PHB引导组织再生膜的仿生矿化研究

实验将PHB通过气流-高压静电纺丝制成无纺膜，利用扫描电镜（SEM）、X射线衍射（XRD）对其形态和结构进行表征。在体外研究中，分别将无纺膜样本浸入37℃1．5倍仿生体液（SBF）中3、7、14、28d后对其表面形态和结构进行表征。结果表明，气电纺PHB无纺膜由超细纤维交织而成，纤维之间有多孔形成；通过气流一静电纺丝之后，PHB的结晶度及晶体的有序度降低；PHB膜在SBF中浸泡3天之后就有矿化结晶在纤维的表面形成，随着浸泡时间的增长，矿化结晶的数目增加，结晶度也随之增高，XRD及FTIR表明形成的结晶为含有碳酸根的磷灰石晶体。