基于802.1x协议的认证网络的设计与实现

文中重点分析了802.1x协议的技术要点、部署流程。结合H3C公司的交换机和Cams认证计费软件,实现为高校校园网络快速部署802.1x认证环境。总结了802.1x环境下的一些性能优化方案与安全措施。     

国内外服务认证发展综述

近年来,伴随着全球由“工业经济”向“服务经济”转型,以及服务贸易的迅速发展,服务认证作为一种保证服务质量,促进服务业和服务贸易发展的重要手段已被世界上越来越多的国家和地区接受,成为国际惯例。文章从分析国际、国内服务认证发展现状入手,在此基础上提出了我国开展服务认证的建议。     

浅谈GB12350《小功率电动机安全要求》标准换版对福建省电机行业的影响及对策

GB12350《小功率电动机安全要求》新旧版本的转换,对电机行业将造成极大的影响。本文主要通过分析此次GB12350《小功率电动机安全要求》换版对福建省电机行业造成的影响及存在问题,并针对具体存在问题提出建议,帮助福建省电机行业顺利完成新旧标准的转换。     

以专业认证导向的生物工程专业实践教学探索

以专业认证为契机,依托江苏省化学工程与技术优势学科,在全国高校生物工程专业设置及建设现状分析基础上,确定生物工程专业人才培养以工科背景,生物科学为基础、工科技能培养为特色,厚基础、宽口径、高素质、技能强、具创新能力的应用型工程技术人才培养方案进行探索与实践,以求提高学生的结合素质,获得最佳的培养效果。     

Assessment of Portuguese thermal building legislation in an energetic and environmental perspective

The aim of this study is to assess the consistency of Portuguese thermal building legislation in terms of energy and environmental performance.To illustrate this, a case study has been carried out for different scenarios of a dwelling home located in an extreme climate zone (I3, V1 north) in Portugal with a T3 typology: four occupants and net floor area of 150 m², modelled according to Regulation Thermal Performance Characteristics of Buildings and a Life Cycle Assessment approach.The results show that the Portuguese thermal building legislation can be considered consistent in terms of energy efficiency and environmental performance if we take the damage categories into account - “human health” or “ecosystem quality” or the impact category - “emission into air”. It cannot be considered consistent if we take the damage category into account - “resources” or the impact category - “CO₂ eq” (equivalent carbon dioxide emissions)/“climate change”/“global warming”.     

Application of energy rating methods to the existing building stock: Analysis of some residential buildings in Turin

The objective of this work is to contribute to the recent standardisation activity, finalized to apply the Energy Performance of Buildings Directive (EPBD). Through the energy assessment of some residential buildings in Turin (Italy), the work investigates the application of the calculation methods that have been specified in the recent European standard for the so-called “standard energy rating”. A comparison of the “calculated energy rating” with the “measured energy rating” is used to investigate the effect of user behaviour and weather conditions. Moreover, in order to draft the energy certificate and make an appropriate classification, the last part of the work investigates the way to find energy reference values of the building stock, through the study of the correlation between the input and the output data of an energy rating and the comparison of the analysed buildings.     

Sampling strategies for assessing lameness,injuries, and body condition score on dairy farms

Our objective was to evaluate how sampling strategies (i.e., how many cows to sample and which animals to include) used in 4 dairy cattle welfare assessment programs affect the classification of dairy farms relative to thresholds of acceptability for animal-based measures. We predicted that classification performance would improve when more cows were sampled and when selecting from all lactating cows versus when some pens were excluded. On 38 freestall farms, we assessed all 12,375 cows for lameness, injuries on the tarsal (hock) and carpal joints, and body condition score and calculated the farm-level prevalence for each measure. Based on approaches used in the industry, we evaluated 6 sampling strategies generated using formulas with precision (d) of 15, 10, or 5% applied to either a single high-producing pen or all lactating cows; an additional sample was included with d = 10% applied to the entire herd, selecting lactating cows in proportion to their representation in the herd. For each sampling strategy, cow records were selected randomly (in 10,000 replicates) to calculate prevalence. The strategy of assessing all cows in the high-producing pen was also compared. Farms were classified as meeting (below) or failing to meet (above) thresholds of ≤15% moderate lameness; ≤20% moderate carpal or hock injuries; <10, <5, and ≤1% severe lameness; or injuries on the carpus or hock; and <5, <3, <1, or 0% thin cows. For each measure and threshold, we calculated pooled percent agreement, kappa, sensitivity, specificity, and positive and negative predictive value for each sampling strategy using true prevalence as the gold standard for herd classification. Across measures and thresholds, classification performance increased with the number of cows sampled [i.e., when narrower precision values (d = 5 vs. 10 vs. 15%) were used in the sample size calculation]. Because narrower precision values can dramatically increase sample size, assessment programs may need to consider both feasibility and the degree of misclassification they will accept. Applying the formula directly to lactating cows performed better than applying it to the entire herd and then selecting lactating cows in proportion to their representation in the herd. Farm classifications were similar whether cows in the hospital pen were included or excluded from the sample. Selecting all cows from the high-producing pen resulted in classifications similar to when including all lactating cows, suggesting that assessing cows from the high-producing pen may serve as an acceptable proxy for all lactating cows on the farm.     

模糊数学在HACCP认证有效性评价中的应用

目的解决HACCP体系认证有效性评价问题。方法根据认证有效性评价要素的特点,选择合理的评价因子,采用模糊综合分析法建立模型,对认证有效性的质量进行综合量化评价,并以实例验证模型与方法的可行性。结果模糊综合评价法可以对企业HACCP体系认证有效性进行准确的定量评价。结论可以运用模糊数学定量方法对认证有效性进行评判,进一步规范认证活动。     

Non‐linear ultimate strength and stability limit state analysis of a wind turbine blade

According to the design codes for wind turbine blades, it is sufficient to evaluate the blade's limit states using solely a linear analysis. This study, however, shows the need of non‐linear analyses in blade design. Therefore, a geometrically non‐linear structural response of a 34 m blade under flap‐wise loading has been compared with a linear response to determine the blade's resistance in the ultimate strength and stability limit states. The linear analysis revealed an unrealistic failure mechanism and failure mode. Further, it did not capture the highly non‐linear response of the blade that was measured in an ultimate full‐scale test to failure and determined by a geometrically non‐linear analysis. A design evaluation in accordance with the least stringent Germanischer Lloyd (GL) requirements has been compared with non‐linear approaches proposed by GL and Eurocode, which require the application of an imperfection. The more realistic non‐linear approaches yielded more optimistic results than the mandatory linear bifurcation analysis. Consequently, the investigated blade designed after the lesser requirements was sufficient. Using the non‐linear approaches, considering inter‐fibre failure as the critical failure mode, yielded still a significant safety margin for the designer (7–28%). The non‐linear response was significantly dependent on the scaling of the imperfection. Eurocode's method of applying an imperfection appeared more realistic than the GL method. Since the considered blade withstood 135% of the design load at a full‐scale test to failure and the blade has operated successfully in the field, GL's safety factors combined with the imperfection size may be too conservative. Copyright © 2015 John Wiley & Sons, Ltd.     

MANET自组织按需认证模型的研究

构建安全可信的MANET 必须考虑到其自身的特性。目前关于MANET 的安全认证研究大多是利用中心认证服务器为用户颁发证书,较少考虑到MANET 自身的自组织特点,很难完成网络的快速部署。结合MANET 的特性,提出一种自组织按需式认证方案。该方案不需要中心认证服务器,充分利用节点自身功能,在完成身份认证的同时具有良好的伸缩性。