Censoring Methodologies and Censored Data Analysis with Applications in the Engineering and Environmental Sciences

审查方法和审查数据分析在工程和环境科学中的应用

• 批准号: RGPIN-2015-06112
• 负责人: Davies, Katherine
• 金额: $ 0.8万
• 依托单位: University of Manitoba
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2020
• 资助国家: 加拿大
• 起止时间: 2020-01-01 至 2021-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=708047
• 关键词: Censoring; Methodologies; Censored; Data; Analysis

Censoring occurs when information about observations is either missing or only partially available. There are various types of censoring, some of which are incorporated into the design of a study, some of which occur naturally and one has no control over. Censored data arise in various fields, ranging from clinical trials in the pharmaceutical industry, to life-tests in the engineering sciences, to the modelling of the spread of a forest fire in the environmental sciences. It is therefore crucial to have the necessary tools to analyze such data and make useful inferences. A life-test, wherein an engineer puts units on test and attempts to make useful inferences about the units' lifetime distribution, is an effective technique employed in reliability analysis. In these tests, some type of censoring is often employed to save resources like time and money. One particular type of censoring is progressive censoring, which is a focus of this research program. In a progressive censoring experiment, surviving units are randomly removed throughout the life-test according to a prespecified scheme.  This type of censoring can be part of the design of a life-test and is more versatile than the traditional types of censoring, and hence is particularly useful.  On this topic, I introduce restricted progressive censoring schemes as well as investigate one-step plans, which are special plans entailing surviving units being randomly removed at one failure time. Despite the restrictive nature of these two types of censoring, these plans have particular benefits from practical points of view. Research departments in companies like Bombardier Inc., where reliability of components is critical and censoring is needed, will be able to benefit from this work. Alongside censoring methodologies is censored data analysis. Here, I focus on various non-parametric methods, that is, methods wherein little is assumed about the underlying distribution of the data. A particular class of tests are rank-based tests, i.e., some ordering of the data points is utilized. While such tests are well established in the literature, they have only recently been explored in the case of multi-dimensional data. My work thus investigates the use of such tests in the case of multivariate censored data where censoring occurs according to different mechanisms. This is especially important in the environmental sciences where many naturally occurring processes can be modelled as multi-dimensional point processes where oftentimes, some sort of censoring has occurred. For this reason, agencies addressing environmental concerns, such as Manitoba Hydro or Environment Canada, will find my work useful. This research program makes significant contributions to the areas of censoring methodologies and censored data analysis. Spanning inference, experimental design and data analysis, this work provides ideal problems to work on with students.

删失发生在有关观测的信息缺失或仅部分可用时。有各种类型的审查，其中一些被纳入研究设计，其中一些自然发生，一个没有控制。删失数据出现在各个领域，从制药行业的临床试验，到工程科学中的生命测试，再到环境科学中的森林火灾蔓延建模。因此，至关重要的是要有必要的工具来分析这些数据，并作出有用的推论。寿命试验是可靠性分析中的一种有效方法，工程师在试验中对部件进行寿命试验，并试图对部件的寿命分布作出有用的推断。在这些测试中，通常采用某种类型的审查来节省时间和金钱等资源。一种特殊类型的审查是渐进审查，这是本研究计划的重点。在逐步截尾试验中，存活的单元在整个寿命试验过程中按照预先设定的方案被随机删除。这种截尾可以作为寿命试验设计的一部分，比传统的截尾类型更通用，因此特别有用。在这个主题上，我介绍了限制逐步截尾方案，并研究了一步计划，其是需要在一个故障时间随机移除幸存单元的特殊计划。尽管这两种审查具有限制性，但从实际角度来看，这些计划具有特别的好处。庞巴迪公司等公司的研究部门，在组件的可靠性至关重要且需要审查的情况下，将能够从这项工作中受益。 除了审查方法，还有审查数据分析。在这里，我专注于各种非参数方法，也就是说，其中很少假设数据的基本分布的方法。一类特殊的测试是基于等级的测试，即，利用数据点的某种排序。虽然这样的测试是建立在文献中，他们最近才被探索的情况下，多维数据。因此，我的工作调查使用这样的测试在多元删失数据的情况下，根据不同的机制发生删失。这在环境科学中尤其重要，许多自然发生的过程可以建模为多维点过程，其中经常发生某种审查。出于这个原因，解决环境问题的机构，如马尼托巴水电或加拿大环境部，将发现我的工作是有用的。 该研究计划对删失方法和删失数据分析领域做出了重大贡献。跨越推理，实验设计和数据分析，这项工作提供了理想的问题，与学生一起工作。