电力月负荷的混沌趋势组合模型预测

针对电力月负荷同时具有趋势增长性和季节波动性,使负荷表现出复杂的非线性特征,从而提出了电力月负荷的混沌趋势组合模型。以四川省全省月负荷序列为例,把原始电力月负荷序列分解为趋势序列和剩余序列。通过计算剩余序列的混沌特征量,识别出剩余序列的混沌特性。在此基础上,利用混沌趋势组合模型对月负荷时间序列进行预测,实例结果表明,该方法对电力月负荷的预测是可行的。     

小型一体化PLC在气箱式脉冲袋收尘器中的应用

采用HOLLiAS—LEC G3小型一体化PLC对气箱式脉冲袋收尘器的控制系统进行了改造，提高了控制系统的稳定性和灵活性。     

Analysis of PD-generated SF/sub 6/ decomposition gases adsorbed on carbon nanotubes

Chemical byproducts analysis has been recognized as a powerful diagnosis method for SF₆ gas-insulated switchgear (GIS). The authors have previously demonstrated that a carbon nanotube (CNT) gas sensor could detect partial discharge (PD) generated in SF₆ gas. However, PD-generated decomposition gas species, which were responsible for the CNT gas sensor response, have not been identified yet. In this paper, two kinds of experiments were conducted in order to identify the responsible decomposition gas species. At first, the decomposition gas molecules adsorbed on CNTs were analyzed by Fourier transformation infrared (FTIR) spectroscopy. FTIR absorbance was observed around 735 cm^-1 after CNTs were exposed to PD generated in SF₆. In the second experiment, the CNT gas sensor responses to typical SF₆ decomposition products (HF and SF₄) were examined. The CNT gas sensor responded to these gases in the same way as to PD generated in SF₆. SF₄ response was larger than HF response. Based on these results, SF ₄ and SOF₂ emerged as candidates for the responsible decomposition gases. Electrochemical interactions between adsorbed gas molecules and CNT were discussed based on theoretical predictions of molecular orbital calculations. The calculation results suggested that both of SOF₂ and SF₄ could increase the CNT gas sensor conductance     

Engineering better wheelchairs to enhance community participation.

With about 2.2 million Americans currently using wheeled mobility devices, wheelchairs are frequently provided to people with impaired mobility to provide accessibility to the community. Individuals with spinal cord injuries, arthritis, balance disorders, and other conditions or diseases are typical users of wheelchairs. However, secondary injuries and wheelchair-related accidents are risks introduced by wheelchairs. Research is underway to advance wheelchair design to prevent or accommodate secondary injuries related to propulsion and transfer biomechanics, while improving safe, functional performance and accessibility to the community. This paper summarizes research and development underway aimed at enhancing safety and optimizing wheelchair design.     

发电机转子匝间短路故障振动分析与检查

汽轮发电机的转子轴振动信号数据是监测设备安全运行的一项重要技术指标。本文针对一台135MW发电机转子轴振动突变超标故障,进行了相关的机械与电气参数的现场测试,分析诊断设备影响原因,通过现场检查,消除了发电机转子线圈绕组内部重大故障隐患。提供的振动测试分析与处理措施,作为故障诊断分析典例以资参考。     

面向电信运营流程的数据稽核方法

针对电信收入保障的主要任务数据稽核，结合电信运营流程的特点，提出了一种新的数据稽核方法. 该方法抽象了电信运营流程的数据流模型，根据一个数据两处体现的电信业务数据处理和变换的原理，基于数据之间的平衡关系和完整性约束关系，定义出电信运营流程中的数据稽核关系；应用这种数据稽核关系可以检测并诊断电信运营流程不规范造成的故障，更好地支持企业的内控管理.      

圆板拉深时凸缘最大应力变化规律的论证

文章通过微分表达形式，对拉深凸缘最大径向拉应力的变化及其影响因素进行了分析论证，并与目前通用的直接对最大径向拉应力公式作定性解释的方法作了比较。     

浅议我国上市公司中独立董事制度的完善

目前,独立董事制度作为公司治理的一项有效方式,在国际上已成为一种潮流。针对我国上市公司治理结构中存在的问题,本文从独立董事制度的引入着手,叙述其在上市公司的实践,分析其在现状中存在的问题,进一步提出完善独立董事制度的思考和建议。     

Channel identifiability under orthogonal space-time coded modulations without training

Space-time block coded (STBC) transmission has been established as an efficient tool to enhance communication performance over wireless fading channels. The success of STBC decoding relies on accurate channel knowledge at receivers. In this work, we present a channel estimation approach that does not require training data to estimate unknown channels. Focusing on STBC from orthogonal designs, we present channel identification conditions that are largely verifiable in terms of the code and the antenna array configuration. We also develop a simple subspace-based algorithm to identify the unknown space-time channel matrix for complex transmission. Finally, we present simulation test results to illustrate the performance of the proposed method.     

C语言教学中常见的运行错误和逻辑错误

总结了编译器不能发现的常见运行错误和逻辑错误,以帮助初学者能较好的掌握程序调试技巧,提高编程能力.