Keep Them Great

Selected Publications

In regional climate models, how to resolve lake surface temperature is crucial to understanding the hydroclimate in water-dominated regions, i.e. the Great Lakes basin. If no lake model is implemented in the lake grids, a “search” option will be employed to extrapolate lake surface temperature from the closest water point with valid data, e.g. Hudson Bay and the Atlantic Ocean, which can cause obvious biases and even adverse effects. In this study, a one-dimensional thermal diffusion lake model within the Weather Research and Forecasting model is updated with a specific treatment of lake surface albedo for the Laurentian Great Lakes to improve the coupled air-lake model’s performance in the simulation of lake temperature and lake ice.
In Journal of Advances in Modeling Earth Systems, 2016

Recent Publications

More Publications

. WRF-based assessment of the Great Lakes' impact on cold season synoptic cyclones. In Atmospheric Research, 2018.

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. Evaluating and improving modeled turbulent heat fluxes across the North American Great Lakes. In Hydrology and Earth System Sciences Discussion, 2018.

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pain in the butt When OneDrive was installed in a computer, it’s painful using R and Rscirpt in command line. Since the Documents has been hijacked by OneDrive, whenever you open the directory C:\User\YourName\Documents it automatically redirects to C:\Users\YourName\OneDrive - Spectrum Health\Documents. You don’t want to backup 2-GB R library fold to the OneDrive. How to reach the real C:\User\YourName\Documents instead of C:\Users\YourName\OneDrive - Spectrum Health\Documents, you have to go C: drive, then User folder, then YourName folder, then Documents.


ERROR! The server quit without updating PID file
Table 'mysql.role_edges' doesn't exist
Access denied for user 'root'@'localhost' (using password: NO)
  • A: Try mysql_secure_installation and follow instruction to setup new password.
    Credit to StackOverflow.


Why sparse matrix? XGBoost only works with matrices that contain all numeric variables; consequently, we need to one-hot encode our data. (UC Business Analytics R Programming Guide) caret::preProcess uses bagging regression trees for missing values recovery (Yevhen Vasylenko), which requires all numeric variables. There are different ways to do this in R. library(tidyverse) dd <- data.frame(a = gl(3,4), b = gl(4,1,12), c = 1:12, d = sample(c("X", "Y", "Z"), 12, replace = TRUE)) str(dd) ## 'data.


Load library library(tidyverse) library(RPostgres) library(DBI) Connect to PostgreSQL Connect Method 1 with RPostgres con1 <- DBI::dbConnect(RPostgres::Postgres(), dbname = "testdb1", password = rstudioapi::askForPassword("Database password")) dbListTables(con1) #dbWriteTable(con1, "mtcars", mtcars) #dbWriteTable(con1, "flights", nycflights13::flights) rstudioapi::askForPassword requires the password input In the command line (or block-run), there will be popout dialog to input password, In the knit mode, render the RMarkdown file as follows: rmarkdown::render("MyDocument.Rmd", params = "ask") See Parameter User Interfaces In the blogdown, server_site will halt at the above block.


zoo: S3 Infrastructure for Regular and Irregular Time Series (Z’s Ordered Observations) An S3 class with methods for totally ordered indexed observations. It is particularly aimed at irregular time series of numeric vectors/matrices and factors. zoo’s key design goals are independence of a particular index/date/time class and consistency with ts and base R by providing methods to extend standard generics Base Time-Series Objects stats::ts Credit: Time Series Analysis in R Part 1: The Time Series Object by DataSciencePlus




The implementation of National Water Model in the Great Lakes Basin


Improving the 1-D lake model in WRF for the Great Lakes.


I have been a Mentor for the following projects at University of Michigan: