Risk assessment based on fault tree analysis for damaged pipe repair during operation in petrochemical plant     

丛广佩  高金吉  杨剑锋  刘文彬 《天津大学学报(英文版)》2013,19(1):70-78

In petrochemical plant, the in-operation repairing is usually a repairing strategy with pressured inoperation repairing for avoiding huge economic losses caused by unplanned shutdown when some slight local leakage happens in pipes. This paper studies the effects of repairing strategies on the failure probability of the pipe systems in process industries based on the time-average fault tree approach, especially the in-operation repairing strategies including pressured in-operation repairing activities. The fault tree model can predict the effect of different repairing plans on the pipe failure probability, which is significant to the optimization of the repairing plans. At first pipes are distinguished into four states in this model, i.e., successive state, flaw state, leakage state and failure state. Then the fault tree approach, which is usually applied in the studies of dynamic equipment, is adopted to model the pipe failure. Moreover, the effect of pressured in-operation repairing is also considered in the model. In addition, this paper proposes a series of time-average parameters of the fault tree model, all of which are used to calculate node parameters of the fault tree model. At last, a practical case is calculated based on the fault tree model in a repairing activity of pipe thinning.  相似文献   

Trust,reputation and ambiguous freedoms: financial institutions and subversive libertarians navigating blockchain,markets, and regulation     

Inês Faria 《Journal of Cultural Economy》2019,12(2):119-132

This article departs from the post 2008 financial crisis context, from its intersection with technological developments, and from the socio-technical arrangements configured by this conjuncture. It explores plans and actions – of mainstream financial institutions, and of a community seeking for alternatives to centralised economy and governance – for the use of digital platforms supported by blockchain infrastructure. In particular, it explores how such plans and actions relate to conceptions of public and peer trust and how they appear to produce, or reinforce, reputational imaginaries and quantification practices within added value philosophies. By illuminating a tension between the two identified case examples, I seek to render alternative communities’ and financial institutions’ conceptions, imaginaries and practices (more) visible and to analyse their organisational marketing strategies – where there is a pragmatic and discursive operationalisation of technology as well as of trust as means to gain more self-sovereignty in action, while navigating markets and regulated actual world contexts.  相似文献   

国内企业信用风险变化趋势及其管理现状的实证分析     

戴彬 《软科学》2006,20(6):73-75

建立了企业信用风险度量模型,依据两组国内企业的应收账款及其管理状况的调查数据,对企业信用风险变化趋势及其管理现状进行了实证分析;提出了几点提高企业信用风险管理水平,降低企业信用风险损失的启示。  相似文献   

Complexity in Science Learning: Measuring the Underlying Dynamics of Persistent Mistakes     

Ethan Fleuchaus  Adam W. Kiefer  Paula L. Silva 《Journal of Experimental Education》2020,88(3):448-469

Abstract

Mistaken beliefs pose a barrier to science learning. For this reason, it is important to understand the circumstances in which they emerge and change. In the current paper, we apply complexity theory to shed light on the nature of mistaken beliefs. The strength of this approach lies in conceptualizing beliefs as dynamic stabilities, a well-defined construct that can be indexed precisely. For example, Recurrence Quantification Analysis (RQA) can determine the presence of dynamic stabilities by analyzing variability in time-series data. We applied this analytical tool to probe for mistaken beliefs in a beam-balancing task, a task that is known to elicit mistaken beliefs in preschoolers. Using a case-study design with four preschoolers, we tracked children’s hand position with motion sensors as they balanced various beams. The resulting time series of hand position was submitted to RQA, yielding two important results: First, we found that consistent mistakes in trying to balance the beams were not always accompanied by dynamic stability. This undermines the common assumption that overt consistency in task performance is sufficient to conclude the presence of beliefs. Second, we found strong individual differences over time, as children explored the balance beams. Applications to science education are discussed.

• Highlights

• A classical task of beam balancing was used to explore the underlying dynamics of children’s mistaken beliefs.

• Moment-to-moment hand movements were tracked and subjected to a multi-dimensional recurrence quantification analysis (RQA).

• Dynamic stability was captured through percent laminarity (%LAM), a measure of rigidity in children’s explorations.

• The RQA measure of %LAM shed light on patterns of stability that were not available from the analysis of overt behavior.

• In line with complexity theory, a model of persistent mistakes is offered that has important implications for science education.

  相似文献   

黄河下游经济-人口-资源-环境和谐发展水平评估     

刘建华  黄亮朝  左其亭 《资源科学》2021,43(2):412-422

随着工业化和城镇化的快速推进,黄河下游经济、人口、资源、环境关系复杂,矛盾日益突出,定量评估其和谐发展水平对黄河下游高质量发展具有重要意义。本文从经济、人口、资源、环境4方面构建和谐发展水平评估指标体系;采用“单指标量化-多指标综合-多准则集成”评价方法（SMI-P方法）,评估黄河下游河南、山东沿黄17个城市2010—2018年经济-人口-资源-环境和谐发展水平;利用雷达图、箱线图分析其时间变化过程,利用Kriging插值法分析其空间变化过程。结果表明：①黄河下游总体和谐水平不高,但逐年稳步提升;经济子系统发展指数最高,环境子系统次之,人口和资源子系统发展指数较低;②和谐发展水平的空间分布,呈现以郑州和济南为中心的高水平聚集区、两省交界城市的低水平聚集区,其他地区为中等水平。最后,结合黄河下游特征,根据不同的聚集区分析其和谐发展过程中的优劣态势,并从结构调整的角度提出促进黄河下游和谐发展的建议。本文旨在通过量化黄河下游经济-人口-资源-环境和谐发展水平,为黄河下游和谐发展提供数据支持和政策建议。  相似文献   

我国企业资产风险管理的评估及量化研究          下载免费PDF全文

芦笛  张晓明 《科研管理》2014,35(12):120-128

已有的风险管理研究成果和企业风险管理实践,主要集中于经营风险(产品风险、价格风险等)、财务风险(支付风险等)和资本市场风险管理方面。本文独辟蹊径,从资产风险管理角度研究我国企业所面临的风险。首先,本文对资产的特性进行了辨析——收益性和风险性,其次进行了实证分析,界定了企业资产风险的概念和表现,构建了资产总风险计量模型,并阐述了该方法具体应用案例,最后有针对性地提出了资产风险规避方面的建议。  相似文献   

Quantifying the immeasurable: A reflection on sport,time and media     

Hibai Lopez-Gonzalez 《体育哲学杂志》2013,40(3):347-362

In the last century, professional sport has experienced a process of standardization that has favoured the development of its two most recent characteristics: the quantification and the pursuit of records, as Guttmann exposed in From Ritual to Record (1978). This article reflects on the ramifications that those characteristics have had in the sport consumption of sport in recent times, focusing particularly on the temporal consequences. The work proposes an ‘evolutive time’ perspective to understand the double fundaments of the sporting temporality: its cyclical dimension of recurrences and familiar elements; and its linear dimension of newness and uniqueness. The argument is that sport draws on elements derived from quantification and records such as time serialization and time disruptions in order to produce a globally appealing and intelligible commodity.  相似文献   

高校科研业绩量化考核体系的构建     

胡涛 《科技管理研究》2012,32(14):153-156

在高校普遍实行岗位聘任与考核制度的背景下,从考核体系构成、考核指标选取、考核目标的制定、考核方法的选择等方面入手,提出建立较为合理、科学并具有可操作性的考核体系,为高校科研业绩考核提供方法参考与政策建议。  相似文献   

构建高校图书馆馆藏等级结构体系与量化模型的思考   总被引：4，自引：0，他引：4  

李雪琴 《晋图学刊》2008,(5):12-14,23

确立高校馆藏发展等级及重点,细化整体馆藏中个体文献的相对收藏数量,是优化文献资源采选工作必须考虑的重要步骤。本文旨在思考以《中国图书馆分类法》中的基本类目为依据,从学科角度出发,建立一个广泛适用的,以利于对已有馆藏进行合理性评价及操作指导,并为文献资源采选提供量化依据的馆藏结构体系与量化模型,以期为高校图书馆的馆藏建设与发展提供参考。  相似文献   

地矿勘查信息化与地矿信息科技学科建设     

吴冲龙  刘刚  田宜平  张夏林  李伟忠 《中国地质教育》2005,14(1):32-35

“地矿勘查信息化”是指采用信息系统对传统的地矿勘查工作主流程进行充分改造, 实现全程计算机辅助化, 数据在各道工序间流转顺畅、充分共享。“地矿信息科技”学科的形成和发展, 既是地矿勘查的信息化和地质学定量化发展的需要, 也是地球信息科学和地理信息科学学科形成发展的推动。为满足地矿勘查的信息化和地质学定量化进程, 适应地球信息科学发展的形势, 应当在重视并加强地矿勘查工作信息化的理论研究和技术开发的同时, 不失时机地创办“地矿信息科技”本科专业, 并加紧进行这一学科体系建设、专业建设和人才培养。  相似文献