析架空输电线路上倍容导线的选择

架空输电线路项目扩容改造,当采用倍容导线时,需在技术和经济上对倍容导线进行比较分析。文章对这种导线的种类、特性情况作了介绍,通过在220kV线路上对倍容导线的选择分析,为同类案例的处理提供了借鉴和参考。     

连续碳分CO2吸收率分析及探讨

本文简述了CO2 气体吸收率的测定原理 ,着重分析了影响连续碳分CO2 气体吸收率的因素 ,提出了提高连续碳分CO2 气体吸收率的途径     

逆变电源的可靠性及其提高途径

影响逆变焊接电源可靠性的因素是多方面的.如产品的设计和生产等各个环节.根据实践经验提出了解决可靠性问题的一些有效途径和方法.     

用PID控制弧焊逆变电源的试验研究

本文介绍了对逆变电源进行数字PID控制的原理和方法,分析了采样周期、PID参数及不同的焊接工况对控制特性的影响。试验表明,只要恰当地选择PID(或PI)参数,不仅能实现高精度的恒流控制,而且能使系统的动态性能显著提高。     

探究用电检查管理中营配信息集成的重要作用

随着我国经济和科学技术的不断发展,用电检查也应从传统的实地管理模式转为自动化、信息化的管理模式。详细阐述、分析了营配信息集成在用电检查工作中的作用。     

现代商业区建筑供配电设计要点及对策初论

在经济的推动下,商业区数量日益增多,空间布局更加紧凑,用电量也随之大幅增加,管理更为困难。因此,要重视商业区建筑的供电配电。介绍了商业区建筑的特点,然后结合实际案例对其供配电进行了设计。     

A novel approach to generate MCQs from domain ontology: Considering DL semantics and open-world assumption

Ontologies are structures, used for knowledge representation, which model domain knowledge in the form of concepts, roles, instances and their relationships. This knowledge can be exploited by an assessment system in the form of multiple choice questions (MCQs). The existing approaches, which use ontologies expressed in the Web Ontology Language (OWL) for MCQ generation, are limited to simple concept related questions — “What is C?” or “Which of the following is an example of C?” (where $C$ is a concept symbol) — or analogy type questions involving roles. There are no efforts in the literature which make use of the terminological axioms in the ontology such as existential, universal and cardinality restrictions on concepts and roles for MCQ generation. Also, there are no systematic methods for generating incorrect answers (distractors) from ontologies. Distractor generation process has to be given much importance, since the generated distractors determine the quality and hardness of an MCQ. We propose two new MCQ generation approaches, which generate MCQs that are very useful and realistic in conducting assessment tests, and the corresponding distractor generating techniques. Our distractor generation techniques, unlike other methods, consider the open-world assumption, so that the generated MCQs will always be valid (falsity of distractors is ensured). Furthermore, we present a measure to determine the difficulty level (a value between 0 and 1) of the generated MCQs. The proposed system is implemented, and experiments on specific ontologies have shown the effectiveness of the approaches. We also did an empirical study by generating question items from a real-world ontology and validated our results with the help of domain experts.     

基于改进FAHP的电力通信网可靠性评估方法研究

论文阐述了可靠性的一般评估方法,在借鉴TMN管理模型的基础上,对电力通信网可靠性进行了分层,构建了可靠性综合评估指标体系.为减少指标体系权重的主观性,提高评估结果的客观性和可信性,提出了一种改进的FAHP综合可靠性评估方法.该方法基于对数最小二乘法(LLSM)进行模糊权重计算,利用限位系数法来实现评估结果的解模糊过程,实例评估验证了该方法的有效性和可行性.最后对电力通信网可靠性的研究方向给出了建议.     

开关电源加速贮存寿命方法研究

开关电源具有体积小、重量轻、效率高等诸多优点,凭借其自身的诸多优势,开关电源已经广泛应用于航空航天、通信、以及电子类。由于应用领域的广泛性,开关电源的可靠性引起了人们的重视。论文以阿伦尼斯(Arrhenius)模型为基础,设计了一整套针对开关电源的可靠性评价和寿命预计的试验方案。该方案对试验器件施加温度应力,加速器件的失效过程,并通过一定的加速模型和统计分析方法,外推出正常工作条件下产品的寿命特征。