基于案例推理的大型养路机械故障诊断系统

为实现铁路大型养路机械(简称"大机")故障的智能检索和诊断,使用基于案例推理(CBR)的思路分析和设计用以实现这些目的的系统。阐述案例的表示和构建方法。提出捣固车的故障案例模型构建方法。设计捣固车故障诊断的CBR系统。给出带权值的k-近邻法的案例相似性检索方法。提出大机故障诊断智能决策系统,采用定性和定量检索相结合的方法。故障诊断系统能够进行案例的定性、定量和混合检索。用捣固车的具体故障案例,验证所设计的系统的可行性。诊断系统检索得到的故障类型与依据现场采集的数据判定的故障类型基本一致,能够进行案例调用和修改。     

基于范例推理的灾害性地震应急物资需求预测研究

基于范例推理(CBR)理论,利用最近相邻法和粗糙集理论搜索相似度最高的主震历史范例,分析各主要物资需求量的影响因素,预测当前范例主震期应急物资需求量。通过序贯决策,采用马尔科夫预测模型预测余震类型,进而搜索余震历史范例,预测余震期应急物资需求量。以"玉树"地震为例,运用该方法估算地震发生后食物类、生活用品类、药品类、工程机械类的需求量。     

火灾试验分布式数据采集系统的开发与应用

火灾试验能真实的模拟建筑物火灾场景,为了获取火灾试验过程中温度场、气体浓度场等数据,设计开发了火灾试验分布式数据采集系统。系统采用分布式、多线程等技术手段,实现了数据的实时采集显示和存储,实时性高,数据传输快,冗余数据少。系统的建立具有较高的实用价值,为建筑物通风排烟系统有效性的检验提供了支撑。     

BOTDR光纤温度监测技术在土木工程中的应用研究

布里渊光时域反射计(BOTDR)是一种新型的分布式光纤传感技术。布里渊光频移量不仅与光纤的应变状态相关,还与光纤的温度存在相应的线性关系,因此BOTDR可以用作分布式的温度监测。本文对基于BOTDR的分布式温度监测技术及其在土木工程中的应用展开了实验研究,研究选用的是美国康宁公司900μm单模紧套光纤,实验标定布里渊光频移量对温度的敏感度为1.43 MHz/℃。通过室内外实验以及在实际隧道工程中的应用,验证了BOTDR的温度测量精度达2℃,因此将该技术应用于分布式温度监测是可行的,长期稳定性良好。     

Relative density of finds for assessing similarity-based maps of orchid occurrence

Similarity-based mapping of the expected distribution of 10 orchid species was conducted in a study area covering 300 km² in south-eastern Estonia. The observation track and species finds were recorded during fieldwork. Absence locations were generated on the line of observation track. Both presence and absence sites having an in-between distance of at least 100 m were used as training data. Expected presence/absence of a species was calculated according to similarity between the predictable location and selected observations (examples) of presence and absence sites. For each species, the machine learning system identified the best predictive sets by selecting the most useful variables out of 136 map and remote sensing features. Similarity-based estimations were evaluated both by training fit and by independent verification data. Reliability of the predictive maps was expressed also by usefulness ratios—the densities of validation find sites (1) in the predicted presence area relative to the density of those in the predicted absence area, and (2) relative to the share of the observation track in the predicted presence area and in the predicted absence area. The predictive mapping was most efficient for Dactylorhiza incarnata, D. russowii, Epipactis palustris, and Goodyera repens. We conclude that the profound coverage of observations on any larger area is unrealistic and the reliability of similarity-based predictive maps depends on the representativity of existing records relative to the diversity of the study area. The investigation showed that the studied species are much more common in nature than the records in the national database indicate.     

Time series modelling of respiratory hospital admissions and geometrically weighted distributed lag effects from ambient particulate air pollution within Kathmandu Valley,Nepal

The distributed lag effects of ambient particulate air pollution exposure on respiratory hospital admissions in Kathmandu Valley are modelled using daily time series data. The extended exposure to PM₁₀ is accounted for by assigning weights to daily average PM₁₀ which decline geometrically as the lag period increases in days. Results show that the percent increase in chronic obstructive pulmonary disease (COPD) hospital admissions and respiratory admissions including COPD, asthma, pneumonia, and bronchitis per 10 μg/m³ rise in PM₁₀ are found to be 4.85% for 30 days lag effect, about 15.9% higher than that observed for same-day lag effect and 3.52% for 40 days lag effect, about 28.9% higher than the observed value for same-day lag effect, respectively.     

分布式光伏-储能系统经济-碳排放-能源效益实证分析——以山东省胶州光伏及其储能系统为例

建立光伏-储能系统成本收益经济模型和全生命周期碳排放和能源分析模型,以静态投资回收期和内部收益率、碳排放强度和碳补偿回收期、能量回收期分别作为经济效益、碳减排效益和能源效益的评价指标,并以山东省胶州农村5,8,10,15kW光伏和11kW-h储能系统为案例,分析增加储能系统后的经济-碳排放-能源特征.案例表明,增加储能...     

分布式认知理论框架下农户土地转出意愿影响因素研究——基于SEM模型的武汉城市圈典型地区实证分析

基于分布式认知理论,从"个人力"、"地域力"、"文化力"三个层次构建农户土地流转认知的影响因素理论框架,利用"武汉城市圈"典型地区土地流转调查数据构建结构方程模型(Structural Equation Model,SEM),定量分析各影响因素在农户土地流转认知中的作用。研究证实:不同农户认知群体之间存在不同流转认知偏好,"无文化的老农民"相对于"有文化的年轻职业者"在土地流转认知中更加保守;农户对土地的需求普遍偏向土地的资产属性和财产权利,农村土地流转具备内在动力;然而,出于对土地社会保障功能的需求,农户不会因为其家庭生产方式和经济来源明显脱离土地而产生强烈的土地转出愿意,农户的家庭生计条件及"土地情节"在一定程度上制约了土地流转;村镇干部"取信于民"是农户获得"安全感",克服风险规避心理促进土地流转认知的最重要因素;流转价格是对农户在土地流转中物质与精神"双重损失"的资金补偿,两者的匹配程度对农户的认知具有重要作用。在此基础上,得出要规范流转程序、健全流转监督机制、保护农民利益,加强农村社会保障制度建设以确保农民获得公平的社会保障,加快推进和支持农村教育以提高农村劳动力素质,建立和完善土地流转制度保障和农业经营扶持机制等政策启示。     

Circular Makerspaces: the founder’s view

Abstract

Makerspaces – open access design and fabrication workshops – provide new contexts for design practice through ‘distributed production’. The global community of makerspaces has evolved quickly and in turn, substantial hype is attributed to its potential for radical sustainable innovation. In this article, we explore this potential in the context of the new ‘circular economy’ agenda. We focus the research on the critical role of makerspace managers/founders who are recognised as gatekeepers to circular practices. The research method is action-led including expert interviews (academics and founders/managers) as well as two generative context-mapping workshops, run at selected makerspaces in collaboration with their founders/managers. We unearth everyday ‘how-to’ guidance to interweave circular practices within makerspaces from the outset by: fostering an enabling culture; building local connections; nurturing individual/community capacities; and stimulating practical know-how. However, while the research reveals immense opportunities to cultivate circular literacy from within makerspaces, the prospects to ask more profound questions about our economy, through makerspace practices, are found to be compromised by day-to-day concerns. The insights from this research can act as a starting point for future work in this emerging research area.     

Metaphors for the War (or Race) against Climate Change

Despite overwhelming scientific consensus, millions of Americans fail to view climate change as a pressing threat. How can we address this disconnect between science and public opinion? In the present study, we investigated the role of metaphorical framing in shaping attitudes toward climate change. Participants read a brief article that metaphorically described US efforts to reduce carbon emissions as a war or race against climate change, or non-metaphorically described it as the issue of climate change. We further manipulated whether these emission-reduction goals emphasized the relatively near or distant future. We found that, compared to the race frame, the war metaphor made people perceive more urgency and risk surrounding climate change and express a greater willingness to increase conservation behavior, irrespective of the time horizon. Those who read the non-metaphorical report tended to respond in between these two extremes. We discuss the implications of these findings for climate communications.