基于文本挖掘和复杂网络的事故致因重要度评估方法——以房屋市政较大以上事故为例

为充分挖掘事故调查报告中的有效信息,明确安全管理工作的内容.首先,利用文本挖掘分析事故调查报告,采用最小词频阈值文档频改进信息增益评估函数对分词结果降噪,通过回溯特征项在报告中的具体表述,提取事故致因,再构建同义词词库.然后,引入复杂网络以改进TF-IDF,综合事故致因因素的关联特征评估其重要度.最后,以房屋市政较大及...     

Public intervention in rural housing markets

This paper is a revised version of one presented to the Regional Science Association Conference, University of Leeds, September 1983.

The extent of rural poverty is largely hidden, yet mean rural incomes are lower than in urban areas. Equally, the differential between low incomes and high minimum house prices in rural areas not always acknowledged. This paper looks at the planning response to these problems against alternative approaches including discriminatory policies against second home owners in rural areas. The paper concludes by identifying a solution restricting private development and augmenting public‐sector provision in rural areas.     

A New Framework for the Assessment of Animal Welfare: Integrating Existing Knowledge from a Practical Ethics Perspective

When making an assessment of animal welfare, it is important to take environmental (housing) or animal-based parameters into account. An alternative approach is to focus on the behavior and appearance of the animal, without making actual measurements or quantifying this. None of these tell the whole story. In this paper, we suggest that it is possible to find common ground between these (seemingly) diametrically opposed positions and argue that this may be the way to deal with the complexity of animal welfare. The model will have to be acceptable for the different parties that will be affected by it and real benefits for the animal should result from it. This will be the basis of a practical ethical approach. All this can be condensed into a model that essentially is made up out of three basic elements: the classical welfare analysis with an existing welfare assessment tool, an assessment of the stockholder, and an implementation of the Free Choice Profiling technique. This new framework does not pretend to be a different or better animal welfare matrix; it is intended to integrate existing knowledge and to provide a practical tool to improve animal welfare. It identifies whether there are welfare problems on a farm, if present whether these problems are caused by the housing system or the stockholder, and what can be done to improve the situation.     

中国农村地震灾害特点及减灾对策

致灾因子强度和承灾体的脆弱性共同决定了灾情的大小.中国农村乡镇发生地震的概率远远高于大中城市,西藏、新疆、云南、宁夏、青海、甘肃等西部农村乡镇是我国地震灾害最为严重的地区.地震灾害对农村乡镇造成的损失,主要是农村居民住房的破坏,约占总损失的80%以上;其它的20%损失中,又以农村水利工程的破坏损失为主.目前我国农村乡镇居民的住房仍以抗震性能较差的土木、砖木结构为主,开展农村住房地震保险、农村低息住房贷款并加强农村建房的监督管理,是降低农村地震风险、减轻农村地震灾害损失的主要对策.     

Qualitative Stakeholder Analysis for the Development of Sustainable Monitoring Systems for Farm Animal Welfare

Continued concern for animal welfare may be alleviated when welfare would be monitored on farms. Monitoring can be characterized as an information system where various stakeholders periodically exchange relevant information. Stakeholders include producers, consumers, retailers, the government, scientists, and others. Valuating animal welfare in the animal-product market chain is regarded as a key challenge to further improve the welfare of farm animals and information on the welfare of animals must, therefore, be assessed objectively, for instance, through monitoring. Interviews with Dutch stakeholder representatives were conducted to identify their perceptions about the monitoring of animal welfare. Stakeholder perceptions were characterized in relation to the specific perspectives of each stakeholder. While producers tend to perceive welfare from a production point of view, consumers will use visual images derived from traditional farming and from the animals natural environments. Scientists perceptions of animal welfare are affected by the need to measure welfare with quantifiable parameters. Retailers and governments (policy makers) have views of welfare that are derived from their relationships with producers, consumers, non-governmental organizations (NGOs), and scientists. All interviewed stakeholder representatives stated that animal welfare is important. They varied in the extent to which they weighted economic considerations relative to concern for the animals welfare. Many stakeholders emphasized the importance of communication in making a monitoring system work. Overall, the perspectives for the development of a sustainable monitoring system that substantially improves farm animal welfare were assessed as being poor in the short term. However, a reliable system could be initiated under certain conditions, such as integrated chains and with influential and motivated stakeholders. A scheme is described with attention points for the development of sustainable monitoring systems for farm animal welfare in the long term.     

住房资源市场开发途径探析

文章分析了在我国住房改革历史进程中，不同阶段所遇到的问题及其几种成功模式，进一步提出了住房资源开发进程中应采取的包括住房金融等方面的相关措施。     

基于强度折减与刚度退化小净距隧道围岩稳定性研究

运用刚度退化的基本原理和方法,将泊松比ν和弹性模量E进行调整,提出变刚度隧道围岩强度折减法。以某小净距隧道为例,在只调整ν或E、同时调整ν和E、保持ν和E不变4种情况下,探讨了刚度退化对小净距隧道围岩稳定性的影响。结果表明:ν对隧道拱顶下沉、拱底沉降、最大主应力的影响要强于E;隧道两拱脚向内位移随折减系数的增大而增大,内侧拱脚向内位移比外侧拱脚的要大,且在刚度调整时拱脚位移要比保持刚度不变时大;等效塑性应变随折减系数的增大而增大,刚度调整导致等效塑性应变区减小,考虑刚度退化推迟了中夹岩柱塑性区贯通;将变刚度隧道围岩强度折减法应用于小净距隧道工程围岩稳定性评价,可依据安全系数的大小来评判设计的合理性,为支护参数及施工技术的选用提供参考。     

Shelter recovery in urban Haiti after the earthquake: the dual role of social capital

This paper documents the culture‐specific understanding of social capital among Haitians and examines its benefits and downsides in post‐disaster shelter recovery following the 12 January 2010 earthquake. The case study of shelter recovery processes in three socioeconomically diverse communities (Pétion‐Ville, Delmas and Canapé Vert) in Port‐au‐Prince suggests that social capital plays dual roles in post‐disaster shelter recovery of the displaced population in Haiti. On the one hand, it provides enhanced access to shelter‐related resources for those with connections. On the other hand, it accentuates pre‐existing inequalities or creates new inequalities among displaced Haitians. In some cases, such inequalities lead to tensions between the have and have‐nots and instigate violence among the displaced.     

城市生活垃圾收运路线优化的数学模型与算法

给出了城市生活垃圾收运路线优化问题的一般描述,考虑时间窗、车容量等约束,以收运路线总行程最短为目标。建立了该优化问题的数学模型。设计了求解谊问题的单一组合邻域搜索算法。随机邻域搜索算法和变邻域搜索算法三种类型的邻域搜索算法。通过对多组算例的求解实验,结果表明变邻域搜索算法的优化效果明显优于其余类型的邻域搜索算法。     

复杂箱体类构件表面多功能涂层技术研究及应用

目的 解决某产品箱体等复杂构件耐磨、减摩、抗烧蚀、残渣难清理引起的腐蚀等问题。方法 开展协合涂层工艺研究及应用试验验证,通过扫描电镜观察(SEM)、成分能谱分析(EDS)及厚度、硬度、附着强度(热震法)、中性盐雾试验、球盘式摩擦磨损试验等对涂层进行性能测试。结果 该涂层厚度均匀可控,与基体结合力强,在300~500 ℃共5个热震循环后,结合力未受影响。硬度高,超过800HV1.0,与铬镀层相当。耐磨性及耐腐蚀性好,6 000次摩擦磨损试验后,无明显磨痕,中性盐雾1 200 h为评级为8级。通过涂层制备工艺对高频淬火部位性能影响研究分析,摸清了涂层制备对高频淬火部位的影响规律。通过箱体等复杂零件试生产,解决了涂层“发花”及“气馕袋”等制备问题。结论 经多轮产品试验验证,该涂层完全能满足产品使用要求。