中频变压器引起的尖峰电压分析

中频变压器在逆变器中起重要作用,也是引起开关工作时电路冲击响应的主要原因。本文针对ＰＷＭ逆变器,讨论、分析了中频变压器引起的关断尖峰电压,并通过实验验证了磁性材料对变压器性能的显著影响。     

市场力对发电公司收益的影响研究

利用产业经济学的新经验主义产业组织学引入推测变分对发电公司的市场行为进行分析,并定量评估电力市场环境下发电公司所拥有的市场力,论述了市场力的运用,推测变分的设定与发电公司的收益之间的关系。研究表明,发电厂商为了获取高额利润会通过设定自己的推测变分来调整市场力,只要推测变分设定适当,无论成本高低,发电公司都可以获取高额利润。     

双曲线模型在某残积土地基沉降计算中的应用

对于残积土地基的沉降变形,实践证明采用压缩模量的计算结果往往偏大,应采用现场试验得到的变形模量来进行计算。为此,该文以广州某残积土地基的实测资料为例,对其非线性沉降采用双曲线模型来表示,所需计算参数则根据现场载荷试验来确定,最后将计算结果与试验结果进行对比。结果初步表明,双曲线模型法用于残积土地基的沉降计算是可行的。     

一种基于介质加载的地球覆盖波束天线设计

地球覆盖波束天线为低轨卫星与地面终端之间的数据传输建立了通道,文中研究了一种新型的介质 加载地球覆盖波束天线。基于介质加载的方法,文中提出了一种圆极化地球覆盖波束天线设计,该天线由馈电网 络、馈源和介质三部分组成,介质包括底部圆柱部分和顶部半球部分,馈源集成于介质内部。设计的地球覆盖波束 天线工作在C 波段,轴向0°~64°范围内增益在0 dBic 以上,40°方向增益为5. 2 dBic。天线尺寸紧凑,辐射波束具有 较好的空间截止特性,可满足立方星应用。     

Hierarchical learning using deep optimum-path forest

Bag-of-Visual Words (BoVW) and deep learning techniques have been widely used in several domains, which include computer-assisted medical diagnoses. In this work, we are interested in developing tools for the automatic identification of Parkinson’s disease using machine learning and the concept of BoVW. The proposed approach concerns a hierarchical-based learning technique to design visual dictionaries through the Deep Optimum-Path Forest classifier. The proposed method was evaluated in six datasets derived from data collected from individuals when performing handwriting exams. Experimental results showed the potential of the technique, with robust achievements.     

Hierarchically Macro–Microporous Covalent Organic Frameworks for Efficient Proton Conduction

Assembling molecular proton carriers into crosslinked networks is widely used to fabricate proton conductors, but they often suffer losses in conduction efficiency and stability accompanied by unclear causes. Covalent organic frameworks (COFs), with well-defined crystal frameworks and excellent stability, offer a platform for exploring the proton transfer process. Herein, a strategy to construct proton conductors that induce conductivity and stability by introducing bottom-up hierarchical structure, mass transport interfaces, and host–guest interactions into the COFs is proposed. The proton-transport platforms are designed to possess hierarchically macro–microporous structure for proton storage and mass transport. The protic ionic liquids, with low proton dissociation energies investigated by DFT calculation, are installed at open channel walls for faster proton motion. As expected, the resultant proton conductors based on a covalent organic framework (PIL_0.5@m-TpPa-SO₃H) with hierarchical pores increase conductivity by approximately three orders of magnitude, achieving the value of 1.02 × 10⁻¹ S cm⁻¹ (90 °C, 100% RH), and maintain excellent stability. In addition, molecular dynamics simulations reveal the mechanism of “hydrogen-bond network” for proton conduction. This work offers a fresh perspective on COF-based material manufacturing for high-performance proton conductors via a protocol of macro-micropores.     

基于强化学习的列车驾驶曲线节能优化算法

在保证安全和准时性的前提下,自动化列车运行可以有效减少列车耗能。为了灵活应对列车运行种的动态变化,提出了一种基于强化学习的方法,可以优化列车控制策略且不采用之前关于列车动力学的知识和设计的列车速度曲线。这个优化模型将列车节能作为目标,把准点到达、列车限速、停车位置作为限制条件。大量的列车运行经验可以被用来训练深度神经网络直到得到最优化行为价值函数,通过对训练过的神经网络输入状态,可以准确输出每个行为的价值,然后再根据行为价值的大小来选择最优的驾驶策略。     

大气折射引起的雷达定位误差模型

大气折射引起的雷达定位误差是限制雷达精度进一步提高的关键因素之一.针对目前只给出雷达测量参数的折射误差,不能明显给出实际应用中所需要的目标位置偏移误差现状.通过采用我国大气折射率的统计模型和目前公认的高精度的电波折射误差修正方法一射线描迹法,对大气折射引起的雷达定位误差进行了目标位置偏离的计算和拟合,建立了大气折射引起雷达测量目标的位置偏移误差模型,从而为雷达实际使用和精度评估奠定基础.     

基于BACnet/XML的BACnet/WS集成模型的设计与实现

本文基于BACnet/XML协议和BACnet/WS接口标准,提出了一种全新的智能楼宇集成模型,设计和实现了集成模型中的核心BACnet/WS服务组件,通过理论分析和仿真测试验证了集成模型具有良好的系统性能,从而较好地解决了智能楼宇领域中的这一难题.     

Emitter-coupled pair chaotic generator circuit

An emitter-coupled pair chaotic generator is proposed with a control parameter that can be tuned for distinct chaotic behaviors. The proposed circuit is a compact, high-speed implementation of the chaotic map based on the hyperbolic tangent function. It is demonstrated that the circuit and map parameters are analytically related. As an application, we design a random number generator that passes all NIST statistical tests by applying a post-processing to the balanced bit sequence generated by a quantization of the circuit output.