Paradoxical effects of information presentation formats and contextual interference on transfer of a complex cognitive skill

In a 2 × 2 factorial design the effects of (1) information presentation format and (2) contextual interference on training behavior, transfer performance and mental effort were studied for learning troubleshooting skills with a computer-based simulation. Participants studied information about the functioning of an alcohol distillery system (system principles) prior to practicing troubleshooting skills. Regarding the first factor, an expository (Exp) format, in which system principles, examples and a troubleshooting strategy were presented in a textual form, was compared to an inquisitory (Inq) format, in which participants had to predict the behavior of the system after they studied the system principles and in which demonstrations of the troubleshooting strategy were given. With regard to the second factor, a low contextual interference (LCI) condition in which participants practiced to diagnose types of system failures in a blocked schedule was compared to a high contextual interference (HCI) condition, in which different failure types were practiced in a random schedule. The main hypothesis is that the Inq and HCI conditions promote the development of cognitive schemata that enable learners to diagnose a malfunctioning system component by interpreting symptoms in terms of violations of system principles. Hence, they are expected to show higher transfer performance than participants in the traditional Exp and LCI conditions, who are believed to develop schemata containing associations between symptoms and malfunctioning components that are context-bound and less useful for diagnosing new failures. Contrary to the predictions, the traditional conditions (Exp and LCI) showed higher performance on a transfer test two weeks after training. Possible explanations for this result are discussed.     

某型飞机襟翼系统的故障分析及预防

本文介绍了某型飞机襟翼系统的工作原理及其特点，对影响分流集流阀同步精度的因素进行了分析，并提出了相应的解决措施。     

基于GA-BP的移动通信设备故障诊断

针对通信设备故障发生随机性强,影响因素多,对应的故障诊断有高度非线性和不确定性的特点,采用BP神经网络算法,优化的GA-BP神经网络算法和POS-BP神经网络算法分别搭建基站设备故障诊断模型,提取设备故障历史数据进行MATLAB仿真,准确预测设备故障类型,帮助提高代维公司调度管理的智能化水平,提高基站设备运维的执行效率。仿真结果表明：本文的BP,GA-BP和POS-BP神经网络算法都能够实现设备故障类别的预测,且GA-BP神经网络算法相比BP和POS-BP神经网络算法对通信设备故障诊断有更好的适应性。     

试论广播电视中数字微波通信系统的故障分析及排除

通过对广播电视中数字微波通信系统中告警信息、监控系统、环电路以及换盘试验等相应的系统故障分析,明确分析相关系统中的具体故障类型体系,同时实现对了相应系统故障排除。     

热连轧交交变频全数字矢量控制系统故障处理与改造

本文着重叙述了我厂主传动交交变频系统控制装置的构造及其功能,另对一些常见故障进行介绍和分析,并列出一些成功改造试点,供大家参考。     

TDS3000B系列数字示波器维修技术研究

本文通过对TDS3000B系列数字示波器几类常见故障现象的总结归纳，在系统研究仪器自身结构特点和电路组成的基础上，结合日常维修工作实践分析了各类故障具体成因，综合运用比对测量、电路功能性分割、在线追踪等故障测量分析方法，分析测量数据，逆向绘制出仪器局部电路原理图，研究并形成了具有针对性的故障诊断定位方法以及维修关键技术。     

给水管网实时故障诊断的支持向量机模型

为实时诊断给水管网故障,提出了一种基于支持向量机(SVM)的宏观关系模型,用以建立实时监测故障前后给水管网3个节点的水压变化与管网中其他所有未监测节点水压变化的非线性关系,通过对水压变化和等值线分析,可以快速和准确地诊断出故障位置和故障程度.最后,运用给水管网局部破坏状态下水力分析的算法求解一个小型给水管网.     

Drying in the Context of the Overall Process

Abstract

Although drying has traditionally been considered as a unit operation, it is strongly affected by upstream operations such as crystallization and solid–liquid separation, and in turn can affect downstream processes such as gas cleaning and micronization. Process design needs to consider the complete flowsheet and the interactions between the different steps as early as possible. Key points are the particle formation method and the final product specification. The mean particle diameter and particle size distribution are vital parameters throughout the process, as smaller particles and fines make solids handling, dewatering, and washing more difficult. This in turn affects the inlet moisture content to the dryer, and hence the heat duty and performance. Intermediate size enlargement or reduction may be used to give a more easily dried particle or agglomerate. There are important links to the new subject of product engineering, for example in the choice of processing route to achieve a given product quality and specification. The interactions between the different process steps can affect process design, equipment selection and troubleshooting, and this is illustrated by industrial case studies. A holistic approach is proposed to allow the whole solids processing flowsheet to be optimized as an entity, rather than optimising each unit operation in isolation and then finding a conflict between them.     

皮带助卷器液压回路原理设计及故障诊断

通过对冷轧后处理机组皮带助卷器的结构和运动特点的分析,进行了液压回路的设计;利用仿真软件对该液压回路进行动态仿真验证。在现场调试过程中,发现该液压回路不能保压。经排查,最后通过实验的方法找到问题原因。通过该问题的解决过程得知:在设计液压原理时,不但要选择合理的液压回路及阀件,还必须充分考虑油缸的内泄漏对系统的影响,并应提出油缸内泄漏的要求和减小内泄漏的措施。     

全液压平地机平衡箱异响研究

全液压平地机平衡箱采用齿轮传动,易产生齿轮异响。介绍了异响故障的排除方法,从平衡箱产生异响的根源入手,结合齿轮传动特点,分析了设计、加工、装配、转运及存放环节中与异响密切相关的各种因素,针对各种因素提出了消除异响的措施。通过对以上措施的实施,全液压平地机平衡箱的异响得到了有效控制。