The effects of quality-management systems on external quality-assessment performance in Finnish clinical chemistry laboratories

The effects of the implementation of quality-management systems and technological changes on the performance of 23 Finnish clinical chemistry laboratories were studied in external quality-assessment (EQA) schemes organized by Labquality Ltd., Finland, during 1993 to 1999. The investigated serum analytes were sodium, calcium, glucose, cholesterol, and alanine aminotransferase. According to the results, the improvements in analytical quality due to the quality programs were rather small. The effects to the proportions of satisfactory results in terms of precision and deviation from the target value were 5–15% (95% confidence intervals for the proportions ±1–5%). At the same time the laboratories were implementing quality-management systems new technology and characteristics of quality-control materials affected the EQA performance. Both improvements and deteriorations in analytical quality due to these factors were identified. The effects and their total outcomes differed substantially between the five analytes.     

Quality specifications for evaluation and comparison of performance among external quality assessment schemes in occupational and environmental laboratory medicine

Quality specifications (QS) are proposed for lead in blood and for aluminium, copper, selenium and zinc in serum as part of the aim to set standards of performance for laboratories so that results can be demonstrated to be fit for the purpose to which they are applied. The QS were established taking account of the analytical state-of-the-art, physiological variations in the concentrations of the analyte and the clinical purpose for which the assay is to be used. A procedure was devised that uses these QS to give equivalence of assessment among external quality assessment schemes (EQAS), thus avoiding conflicting information which has been demonstrated in the past. Advantages of this procedure are: to provide direct comparison of performance of laboratories taking part in different schemes, to provide equivalence of assessment of laboratory performance necessary to establish mutual recognition agreements, and to demonstrate the fitness for purpose of results from participants.Presented at the Eurachem PT Workshop September 2005, Portorož, Slovenia     

Improving confidence in (Q)SAR predictions under Canada’s Chemicals Management Plan – a chemical space approach$

Abstract

One of the key challenges of Canada’s Chemicals Management Plan (CMP) is assessing chemicals with limited/no empirical hazard data for their risk to human health. In some instances, these chemicals have not been tested broadly for their toxicological potency; as such, limited information exists on their potential to induce human health effects following exposure. Although (quantitative) structure activity relationship ((Q)SAR) models are able to generate predictions to address data gaps for certain toxicological endpoints, the confidence in predictions also needs to be addressed. One way to address this issue is to apply a chemical space approach. This approach uses international toxicological databases, for example, those available in the Organisation for Economic Co-operation and Development (OECD) QSAR Toolbox. The approach,assesses a model’s ability to predict the potential hazards of chemicals that have limited hazard data that require assessment under the CMP when compared to a larger, data-rich chemical space that is structurally similar to chemicals of interest. This evaluation of a model’s predictive ability makes (Q)SAR analysis more transparent and increases confidence in the application of these predictions in a risk-assessment context. Using this approach, predictions for such chemicals obtained from four (Q)SAR models were successfully classified into high, medium and low confidence levels to better inform their use in decision-making.     

结合人眼视觉关注特性的视频质量评价

考虑到人眼视觉关注特性在视频质量评价(VQA)中所具有的重要作用,提出了一种结合人眼视觉关注特性的视频质量评价方法。首先利用三维Sobel算子以及恰可察觉失真模型得到全局显著图,对全局显著图的每个显著像素点构建结构张量来求取一帧的全局质量;然后利用视频运动信息以及人眼中心关注特性求得局部显著图来进行感知加权,得到一帧的局部质量;最后均衡局部与全局质量得到视频中一帧的质量,并采用机器学习的方法获得时域加权模型,对视频帧进行加权,从而得到客观视频质量评价值。在LIVE视频数据库上进行性能测试,得到PLCC(Pearson Linear Correlation Coefficient)为0.827,SROCC(Spearman Rank Order Correlation Coefficient)为0.802,与已有相关算法相比,所提出的VQA方法的评价结果更接近人眼的主观感知。     

装备技术需求多方案优选方法研究

针对单一优选准则带来的装备技术需求多方案优选结果的片面性,建立了由需求满足度、技术先进程度、技术重要度和技术成熟度等构成的指标体系,实现了装备技术需求的多视角综合优选,克服了单一准则下优选方案的偏差。最后通过示例验证了方法的可行性。     

基于灰区间关联分析的银行个人信用优化评估模型

个人信用评估是信贷管理的一项重要工作,科学准确的信用评估有利于银行业的健康发展.采用主客观赋权的方法,给出了一种基于灰区间关联分析的个人信用优化评估模型,利用优化的指标权重值进行评估,可以使评估结果更为合理准确.     

新疆油田非金属管道风险评价

针对新疆油田非金属管道在集输、注水、供水等系统上使用过程中暴露的诸多问题,确定了非金属管道风险事故因素集,建立了基于模糊综合评判法的非金属管道风险评价数学模型,采用层次分析法确定指标权重区间,对非金属管道进行风险评定.通过实例分析表明,管道材质、运行管理及施工质量在非金属管道使用风险中起到主导作用.     

The impact of urban noise on primary schools. Perceptive evaluation and objective assessment

This paper aims to assess the impact of environmental noise in the vicinity of primary schools and to analyze its influence in the workplace and in student performance through perceptions and objective evaluation. The subjective evaluation consisted of the application of questionnaires to students and teachers, and the objective assessment consisted of measuring in situ noise levels. The survey covered nine classes located in three primary schools. Statistical Package for Social Sciences was used for data processing and to draw conclusions. Additionally, the relationship of the difference between environmental and background noise levels of each classroom and students with difficulties in hearing the teacher’s voice was examined. Noise levels in front of the school, the schoolyard, and the most noise-exposed classrooms (occupied and unoccupied) were measured. Indoor noise levels were much higher than World Health Organization (WHO) recommended values: L_Aeq,30min averaged 70.5 dB(A) in occupied classrooms, and 38.6 dB(A) in unoccupied ones. Measurements of indoor and outdoor noise suggest that noise from the outside (road, schoolyard) affects the background noise level in classrooms but in varying degrees. It was concluded that the façades most exposed to road traffic noise are subjected to values higher than 55.0 dB(A), and noise levels inside the classrooms are mainly due to the schoolyard, students, and the road traffic. The difference between background (L_A95,30min) and the equivalent noise levels (L_Aeq,30min) in occupied classrooms was 19.2 dB(A), which shows that students’ activities are a significant source of classroom noise.