建设生态文明 先要转变观念

<正>经济发展模式的根本转变党的十七大第一次提出了"生态文明"的概念,并且把建设生态文明列入全面建设小康社会的奋斗目标,这是我国经济发展模式的根本转变,是我们党对发展理念的理论升华,具有十分重要的现实意义和深远意义。     

Advances in Digital Front-End and Software RF Processing： Part II

In the first editorial of this two-part special issue, we pointed out that one of the biggest trends in wireless broadband, radar, sonar, and broadcasting technology is software RF processing and digital front-end [1]. This     

Soft eigenvalue assignment with limited disturbance feedforward and state controller norm

The method of softly assigning eigenvalues is attractive for design problems where constraining the control effort and disturbance feedforward is more important than following the exact pole location.     

铜厚膜环行器的研制

采用新型的在大气气氛中烧结的铜厚膜多层导电浆料,应用厚膜混合技术制作了2。2GHz和2.8GHz的环行器。其性能指标可与同类型采用薄膜贵金属制作的环行器相媲美,且工艺简单,成本低及生产周期短。     

资源卫星接收站高分辨率实时快视处理

本文较系统地阐述了资源卫星地面接收站对遥感图像的高分辨率实时快视处理方法。文中提出了主要针对接收美国Landsat卫星TM数据的实时快视系统方案,其具有1024×1024显示的高分辨率,兼顾了多功能、低成本、简易性和对不同类型遥感数据快视处理的兼容性等特征,为我国已建的和即将兴建的资源卫星接收站配置实时快视系统提供了一条有效途经。     

Embedded Scenario Clustering for Wind and Photovoltaic Power, and Load Based on Multi-Head Self-Attention

The source and load uncertainties arising from increased applications of renewable energy sources such as wind and photovoltaic energy in the power system have had adverse effects on optimal planning and dispatching. Models for generating typical renewable energy and load scenarios are constructed to reduce such effects and improve the applicability of a planning and optimal dispatching model of power systems with a high proportion of renewable energy. The traditional clustering-based model for representing such scenarios cannot handle high-dimensional time-series data and consequently the feature-related information obtained cannot fully reflect the characteristics of the data. Thus, a deep convolutional embedded clustering model based on multi-head self-attention is proposed. First, a variational mode decomposition model is optimized to reduce the influence of noise-related signals on the feature extraction. The deep features are then extracted from the data using an improved convolutional autoencoder, and the appropriate number of clusters is determined using the elbow method. Following this, the network parameters are optimized based on the sum of losses during reconstruction and clustering. Subsequently, typical scenarios are then generated based on the optimized network model. Finally, the proposed method is evaluated based on data visualization and evaluation metrics. It is shown that the quality of features and the accuracy of clustering can be effectively improved by the proposed scenario generation method.     

Finite-Elemente-Analyse einer Transversalflussmaschine

An efficient and resource saving method to generate the different angular rotor positions of a transverse flux machine with a 3D finite element model is presented. The calculations are performed with the superelement analysis of the EMAS solver. From the magnetostatic results the torque-position relationships and the stray field energy in the rotor shaft are evaluated in the steady state condition for different values of the excitation current.     

Prinzipien der Powerline Communication

The liberalization of the electricity and telecommunications markets has paved the way for harnessing existing electricity supply networks to transfer data from the low-voltage transformer station right through to every mains socket in a building. Powerline communication (PLC) allows for coupling power supply with data transmission. The modulation or demodulation calls for state-of-the-art, fast chip technologies as well as algorithms. According to powerline companies, the first generation of products is to be launched in the year 2001. Further development of this system depends completely on the regulation of the respective frequency levels. If regulatory measures and the market were to favor powerline technology, electric utility companies could come to play a role as telecom providers.