Having an exact match domain on your primary keyword is pure gold for Google. But will this work for subdomains like dennisyu.wordpress.com?
Regardless, since getting your subdomain on wordpress.com is free, just like at blogger.com, you should do it. At least you can claim your name.
You should include your name as one of the tags, which generates another page to be crawled by Google. And don’t put it under “uncategorized”– choose something.
Finally, write a compelling article at least 250 words long. Link to it from other articles if you can.