光伏构件的传热系数检测

本文首先阐述了建筑围护结构对光伏构件传热性能的要求，然后根据相关标准测试了三种光伏构件，分析影响传热系数的原因，最后分析了三种光伏构件在全国各气候分区的适应性。     

轻集料混凝土集料性质对混凝土性能的影响

选用4种高强陶粒为粗骨料,在相同的配合比条件下,对陶粒混凝土性能进行试验研究。实验表明,混凝土的性能随着陶粒种类的不同而变化,陶粒的形状和表观密度是影响混凝土性能的主要因素。     

An econometric analysis of the effects of the penalty points system driver's license in Spain

This article seeks to quantify the effects of the penalty points system driver's license during the 18-month period following its coming into force. This is achieved by means of univariate and multivariate unobserved component models set up in a state space framework estimated using maximum likelihood. A detailed intervention analysis is carried out in order to test for the effects and their duration of the introduction of the penalty points system driver's license in Spain. Other variables, mainly indicators of the level of economic activity in Spain, are also considered. Among the main effects, we can mention an average reduction of almost 12.6% in the number of deaths in highway accidents. It would take at least 2 years for that effect to disappear. For the rest of the safety indicator variables (vehicle occupants injured in highway accidents and vehicle occupants injured in accidents built-up areas) the effects disappeared 1 year after the law coming into force.     

Multivariate analyses of major and trace elements in 19 species of herbs consumed in Yunnan,China

This study aimed to analyze the concentrations of 10 elements in 19 species of herbs related to medical and edible purpose in Yunnan, China. Microwave-assisted acid digestion was used for all of the dried herbs and element contents were determined by inductively coupled plasma atomic emission spectrometry. The accuracy of this method was validated by analyzing GBW07605 certified reference material. The results indicated that the distributions of element contents were varied over a wide range in the specimens tested. The decreasing sequence of average element content expressed as dry weight was presented as follows: calcium (1740–22,246 µg/g dry weight), magnesium (634–6367 µg/g dry weight), iron (52.8–5707 µg/g dry weight), barium (9.19–465 µg/g dry weight), zinc (10.7–82.1 µg/g dry weight), strontium (8.25–69.8 µg/g dry weight), copper (4.10–36.6 µg/g dry weight), chromium (0.26–13.3 µg/g dry weight), nickel (0.57–14.7 µg/g dry weight), and cadmium (0.11–2.66 µg/g dry weight). The element contents of samples were different depending on several species. However, the accumulations of toxic elements (cadmium, chromium, and nickel) were above the international safety standards limit in most samples. Principal component analysis generated three principal components that explained 77% of the total variance in the data. Similar samples may get together by cluster analysis and could correspond to the result of principal component analysis.     

Ceramic Substrates for High-temperature Electronic Integration

One of the most attractive ways to increase power handling capacity in power modules is to increase the operating temperature using wide-band-gap semiconductors. Ceramics are ideal candidates for use as substrates in high-power high-temperature electronic devices. The present article aims to determine the most suitable ceramic material for this application.     

基于组件技术的事件流引擎通信框架的设计与实现

随着网络规模的增大和通信技术的发展,网络安全、金融和交通等领域已经开始利用事件流技术实现其业务数据的处理及分析。该文针对这些领域复杂的网络环境为事件流引擎设计并实现了一种基于组件技术的通信框架,可以灵活地集成多种通信组件以应对不同的通信环境,并且通过嵌入Esper引擎提供统一的语义封装解析和高性能的事件流业务处理。     

我国主要城市经济发展水平研究

运用主成分分析法对国内9个主要城市的经济发展水平进行了评价,得出了各城市的综合排名结果,并结合聚类分析对各城市经济发展水平进行分类及探讨,依据分析结果,提出了相应的城市建设建议。     

Reconciling continuum and non-continuum data with industrial application

In order to perform data reconciliation, it is important that noises in the data have well-defined distributions. The motivation behind this study was to enable the comparison between a discrete and continuous data set so that means can be compared for gross error over the short term; this required that local variables exhibit similar distributions.A case study was done on a system where non-continuum loads from a dump truck were to be reconciled with two downstream continuum weightometers. An algorithm was developed using the binomial distribution and time delay in order to simulate the effect of the dump pocket.Regression analysis based on principal components was used to evaluate the performance of the smoothing algorithm and to determine the most likely maximum hopper capacity that locates between the two weightometers.     

Effective fault detection and isolation using bond graph-based domain decomposition

The problem of fault detection and isolation in complex plants can be effectively addressed by a hierarchical strategy involving successive narrowing of the search space of potential faults. A bond graph network is one means of achieving a hierarchical strategy based on the physical domains present in the plant. First, the multivariate statistical method of principal component analysis is used to reduce the data dimension. Second, a discrete wavelet transform is applied to abstract the dynamics at different scales. Thirdly, the Mahalanobis distance is applied to calculate the confidence level. Following a conclusion of the existence of a fault, isolation is achieved by comparing the time scale at which the violation occurred to the time scale associated with a physical domain. In the final step, a Bayesian network is employed to describe the conditional dependence between faulty domains and fault signatures. Two examples are presented to demonstrate these concepts.     

Multivariate statistical monitoring of the aluminium smelting process

This paper describes the development of a new ‘cascade’ monitoring system for the aluminium smelting process that uses latent variable models. This system is based on the changes of variability patterns within a feeding cycle which are used to provide indications of faults and their possible causes. The system has been tested offline using 31 data sets. The performance of the system to detect an anode effect has been compared with a typical latent variable model that monitors the change of behaviour at every time instant. The results show that the ‘cascade’ monitoring system is able to detect abnormal events. It was possible to relate each event with specific patterns associated with abnormalities thus facilitating later fault diagnosis.