双碳及能源安全背景下中国电煤月度需求组合预测

双碳发展背景下,准确及时的电煤需求预测有利于国家制定电煤供需计划及能源安全供给。现有研究对电煤月度需求预测的较少,且精度欠佳,难以保证电煤月度需求感知的及时性和准确性。提出由回归加权融合反向传播神经网络、门控循环单元网络和长短期记忆网络的组合预测模型预测我国电煤月度需求。首先采用格兰杰因果检验从月度经济及能源生产因素中筛选显著影响电煤需求的变量。然后构建单一及组合模型进行预测,其中,组合模型权重由回归计算得到。结果表明,相较单一模型,组合预测模型在电煤需求预测中性能更好。     

基于补偿零序压差原理的110kV线路纵向故障保护方案

针对现有保护装置没有计及纵向故障的保护方案的问题,首先分析110 kV负荷站变压器中性点接地和不接地方式下线路的单相、两相断线故障特征。其次依据断线故障特征提出了基于线路双端零序电气量的补偿零序电压差动原理的断线保护方案,实现了断线故障的快速可靠动作。最后在110 kV纵联差动保护装置上增加断线保护逻辑,并在数字仿真系统上建立110 kV负荷站输电系统,验证了所提断线保护方案的有效性。     

列宁灌输理论在高校“四史”学习教育中的运用

列宁灌输理论是马克思主义思想政治教育理论的重要组成部分,也是列宁对马克思主义灌输理论的继承和 发展。现阶段,在高校“四史”学习教育中运用列宁灌输理论既有重要的理论意义,又有重要的现实意义。通过提高灌输主 体的综合素质、科学对待新时代灌输客体的新特点、创新灌输方法等途径,不断推进列宁灌输理论中国化、时代化,增强 “四史”学习教育的实效性。     

Super-orthogonal space-time code design based on the trellis diagram integrated operation

By studying the super-orthogonal space-time coding designs for 2 transmit antennas and superquasi orthogonal space-time coding designs for 4 transmit antennas,a novel super-orthogonal space-time coding design for 4 transmit antennas is proposed.By exploiting the inherent structure association between OSTBC and QOSTBC,the proposed schemes can obtain the full-rate and good performance while keeping the coding complexity as super-orthogonal space-time coding schemes for 2 transmit antennas.Simulation results d...     

Asynchronous cooperative communication systems:A survey on signal designs

Cooperative communications is a promising technique for future high speed wireless communications.These systems may be formulated as virtual multi-input multi-output (MIMO) systems where spatial/cooperetive diversity is a key advantage. However,different from MIMO systems,one of the major chal- lenges for cooperative communications systems is that the cooperative transmissions in cooperative systems may be neither time nor frequency synchronized,since the transmissions are from multiple cooperative nodes at...     

Performance analysis and partner selection for cooperative diversity based on MQAM modulation

An adaptive decode-and-forward (DF) cooperative diversity system based on quadrature modulation is proposed, in which each user is allowed to transmit its own and the partner’s data simultaneously via the in-phase and quadrature components of M -ary quadrature amplitude modulation (MQAM) constellation. Cooperative transmission in this way can avoid the bandwidth expansion in traditional cooperative systems. The closed form expression of the average bit error rate (BER) performance is derived in terms of the...     

海洋地质数据库应用模型构建方法

随着海洋地质调查程度的不断深入,海洋地质调查业务越来越多,如何合理地管理使用海洋地质调查数据成为研究热点。文章以面向对象的思想为基础,借鉴POSC Epicentre数据模型和中国石化石油勘探开发数据模型建设思路,提出了面向业务的海洋地质应用模型标准体系架构,介绍了海洋地质调查数据库应用模型的构建方法,对海洋地质调查业务进行系统的分析,详细描述了海洋地质业务模型的分析方法,设计了逻辑模型的构建流程。以海洋地质调查地球物理业务为例,构建了其业务模型和逻辑模型,可以弥补现有海洋地质数据库系统存在的缺陷,提高数据服务的效率。     

Research on Visual Virtual Design Platform for NC Machine Tools

1 Introduction With the forming of the global integrated environment ,the market competition of machine tools will be-come more intensely. At present ,the technology of the domestic machine tools is still behind relatively. Withregard to the designing method, we are still at the designing phase of experience ,static state and analogy. Weseldomthink of the structural dynamic characteristic ,andseldomuse the advanced designingtechnique and opti-mization software .Sothe quality and productioneff…     

An Open CNC Based Integrated Measuring,Modeling and Manufacturing System Architecture

1 Introduction Multi-function alityis one of trends of modern machine tools to meet the needs of the smaller batch produc-tion. And the machinesintegrated withthe measuring, modeling and manufacturingfunction can provide betterversatility tothe workshop. Withsuch a machine one caneasily complete the tasks of digitalization,revision andi mprovement ,digitalized copy and prototyping of products ,artware and some cultural relics .Modern CNC control technology and i mage processing techniques pr…     

The Remote Product Check and Acceptance Technology Based on Web

1 Introduction The remote product check and acceptanceis ani mportant part of the e-purchase ,andthelast essential linkto a successfully e-purchase .By tri mming and opti mizing the traditional purchase process and the automation ofrepetitive work,the e-purchase systembased on Internet technology greatly raises the efficiency of bothsides ofthe business ,reduces the cost and the cycle of order form disposal as well as the items on stock of both sideswhich eventuallyleads tothe falling of the p…