一种在ASP.NET中调用存储过程的新方法

提出了一种新的在ASP.NET中调用存储过程的方法。该方法和通用方法相比,具有可以提高开发速度,代码容易维护的优点。     

一种惯性平台自动调平系统的设计

为了缩短惯性平台的调平时间提高调平的精度,本文首先建立了平台的数学模型,在此基础上建立了基于PID(Propor-tional-Integral-Derivative)神经元网络控制的平台调平系统,该系统主要由水平传感器、PID神经网络控制器、D/A和A/D转换模块、变频器和电机组成,四条支腿同时升高调平.仿真结果表明,在x方向和y方向水平偏差角度分别不超过2°时,调平时间小于50s,调平精度小于2,调平过程中平台稳定,无虚腿现象,实现了机电式四点调平.经过长期使用,系统运行稳定,可靠性高.该控制器可应用于不同的调平系统中.     

Prosthetic valve endocarditis: superiority of surgical valve replacement versus medical therapy only

The objective of our study was to assess the long-term outcome of patients with prosthetic valve endocarditis. We used a multicenter, prospective, observational study design. Six university teaching hospitals with high volume cardiothoracic surgery participated. Seventy-four patients with prosthetic valve endocarditis as defined by explicit, objective criteria were selected for participation. All patients were followed up prospectively for 1 year. Thirty-one percent and 69% had development of endocarditis within 60 days of valve insertion ("early") and after 60 days ("late"), respectively. The most common causes were Staphylococcus epidermidis (40%), Staphylococcus aureus (20%), streptococcal species (18%), and aerobic gram-negative bacilli (11%). Physical signs of endocarditis (new or changing murmur, stigmata, emboli) were seen in 58%. At 6 months and 12 months, mortality was 46% and 47%, respectively. Surgical replacement of the infected valve led to significantly lower mortality (23%) as compared with medical therapy alone (56%), as assessed by both univariate and multivariate analyses (p < 0.05). Improved outcome was seen for the surgical group even when controlling for severity of illness at time of diagnosis. From these findings we conclude that accurate assessment of outcome in prosthetic valve endocarditis requires long-term follow-up of at least 6 months following diagnosis. Surgical therapy warrants greater scrutiny; evaluation in controlled clinical trials is appropriate.     

机械图参数化绘图通用AutoLISP函数设计与应用

介绍在AutoCAD环境下,用AutoLISP语言开发机械图参数化绘图通用函数方法．提出了尺寸公差表输入方式的自动判别模式．函数的建立,可提高编程效率,缩短软件开发周期。程序已在AutoCAD10.0版上运行通过,并应用于换热器CAD项目中,取得了较好的经济效益．     

类氖钼基态到（n＝3，4）88个能级的碰撞强度

采用“快速”扭曲波方法和程序ＭＣＤＷ（九）,计算了类氖钼基态到８８个（ｎ４）激发态能级的电子碰撞激发截面,并与国外完全相对论理论数据进行了详细比较,一般差别在１０％左右,表明作者发展与建立的一套方法和程序不仅实现了“快速”计算而且有相当高的精度。     

A converter-assisting flexible switch topology and its control strategy北大核心

The rapid development of new energy in the distribution network increases its flexibility while making it more complicated to operate and manage the network. For this reason, a novel flexible switch, which is composed of integrated gate- commutated thyristors (IGCT) and parallel voltage converters, is proposed in this paper. Applying virtual synchronous generator (VSG) control on the parallel voltage converterensures smoothness and steadiness while switching from one feeder to another. Firstly, the proposed flexible switch is compared with the flexible multi-state switch and the mechanical switch on their main characteristics. Then, the operating features of the flexible switch before, during, and after feeder fault are analyzed, as well as its switching logic. Finally, the switching process between different feeders is simulated on a control in-the-loop experiment based on RT-Lab. The voltage and current waveforms are obtained under different operating modes and during flexible switching. The experiment resultsshow that the flexible switch has short-term voltage support capability and does not generate voltage and current impulses during the switching process. © 2023, Editorial Department of Electric Power Engineering Technology. All rights reserved.     

基于局部光栅补全的反光物体三维重建

针对结构光三维重建过程中,因表面强反光造成光栅形变而导致的相位误差、重建精度降低的问题,提出一种基于局部光栅补全的重建方法。首先对被测物体自身材料特性以及镜面反射角等引发三维重建点云模型缺失现象的反光因素进行分析。其次在相位展开前,引入局部光栅补全法,对反光区光栅丢失部分进行补全,以相移法加互补格雷码重建法为基础提高相位展开精度。最后,通过搭建单目结构光三维重建系统,对平面度误差在0.5 mm范围内的反光矩形铝合金板进行三维重建。实验表明,本文提出的改进方法可以有效补全因物体表面反光造成的重建缺失,其相位解码信息更加完备,重建率相较于传统方法提升了25%,平面度误差率降低了28.2%。     

考虑风电不确定性的交直流配电网低碳分布鲁棒优化调度

为增加配电网风电的消纳能力,减少碳排放,建立了一种交直流配电网低碳分布鲁棒优化调度模型。分析风电预测误差和预测出力历史数据之间的正相关性,采用混合Copula函数,建立它们之间的联合概率分布,得到风电预测误差的条件概率分布。将交直流配电网解耦为交流和直流子网,以各自综合运行成本最小为优化目标,在交流子网优化模型中引入碳交易机制,建立交直流配电网分散协调优化模型。以得到的风电预测误差的条件概率分布为参考,构建了基于K-L散度的分布鲁棒模糊集。利用拉格朗日对偶理论,将优化模型转化为单层优化目标模型,并利用交替方向乘子法进行分散协调优化求解。基于修改后33节点交直流配电网模型的仿真结果表明所提模型能有效减少配电网侧碳排放量,显著提高风电消纳能力。     

基于过采样和随机森林的高压隔离开关发热故障诊断

云团运动的不确定性使得光伏系统输出功率较难准确估计,从而影响新能源并网的可靠性和经济性。为了有效利用卫星的云观测数据,提出了基于云图特征的超短期光伏发电功率预测模型。利用卷积神经网络对卫星云图进行特征提取,且和通过相关性分析后的4种气象特征进行融合,作为光伏发电功率预测模型输入。在此基础上,通过卷积神经网络解析这些特征之间的空间联系,并使用长短期记忆网络实现对光伏输出功率的时间序列预测。此外,考虑到一个自然日中不同时段数据对预测影响不同,引入多头注意力机制来确定关键时间点与关键特征,由此进一步提高所提模型精度。使用光伏电站实际数据以及对应的卫星云图和天气数据,对所提模型的预测效果进行验证。算例分析结果表明,该模型预测精度高且时效性好,特别对于正午辐照较大以及云团运动波动剧烈的时段,模型仍能保证较高的预测精度。     

计及综合需求响应参与消纳受阻新能源的多时间尺度优化调度策略

随着新能源发电技术的高速发展,电网新能源消纳压力日益凸显。与此同时,随着多能转换技术发展,电网与其他类型能源网络的耦合程度不断提高,如何利用不同能源网络灵活性资源消纳受阻新能源,成为当前亟待研究的问题。为此,提出了计及综合需求响应参与消纳受阻新能源的多时间尺度优化调度策略。首先,充分考虑综合能源系统(integrated energy system, IES)特性建立了冷、热、电负荷的多类型需求响应模型。其次,在日前时间尺度,考虑新能源消纳过程中各方利益均衡,建立了基于主从博弈理论的价格型综合需求响应(integrated demand response, IDR)日前优化调度模型;在日内时间尺度,针对新能源日前预测偏差对系统优化影响,建立了考虑激励型IDR日内滚动优化调度模型。最后,通过算例仿真证明了所提策略可深入挖掘多类型负荷需求响应能力,有效提高新能源消纳量。