My researches of interesting are theoretical development as
well as data analysis in the following areas:
Sampling plans; Maintenance; Survival Analysis; Quality Control; Bays’
Estimation; Bootstrap Methods; EM algorithm and sampling plans for life-testing
in industry. The following are short
simply descriptions for each topic.
- Survival
Analysis: Censored data happens
very often in medical sciences and industrial life testing. Survival Analysis and related
comparisons are important research subjects in medical sciences and
industrial life testing. Currently,
I am working on the research to develop new method incorporating frailty
to analyze and compare life-time data (censoring possibly) from two
different treatments; and smooth estimator for Survival Function under
random censored data.
- Quality
Control: In industry, many data are
not normally distributed. Shewhart type control chart is not suitable under this
case. Therefore, new approaches are
needed to setup control charts.
- Bootstrap
method is a re-sampling procedure.
When the sampling distribution for an estimator (or called
estimating function) unknown, bootstrap method usually provides a good
approach to estimate sampling distribution for estimator interesting.
- EM
algorithm is an iterative process for finding Maximum Likelihood Estimator
(MLE) when the complete likelihood function could not be presented in a
closed form or data missing. The
most important is to set up an iterated process which contains finding
expectation and finding maximization.
- Maintenance
strategy combines preventive repair actions at prescheduled times and
minimal repair actions whenever a failure happens. The research contains setting the cost
for the strategy and the optimal preventive maintenance schedules to
minimize the cost for maintenance strategy and estimating the schedules
based on failure times from products.
The research could be implemented by simulation for a failure
model.
- Sampling
plans is to decide the sampling strategy, which includes sample size and
maximal number of nonconforming, such that the producer’s risk and
customer’s risk could be met.