Doggedly

I grew moody, silent, and unsocial, but studied on doggedly and incessantly.

I continued to pound along doggedly. I was grimly resolute.

She was married to someone. He was doggedly determined he would get her.

Unemployment hovered doggedly near 10%.

The announcement was made in Leeds - the largest city in Europe without a mass transit system. It's also a city which has been doggedly pressing (to little avail) for an integrated transport system for two decades.

'Nay,' said Dr Johnson, 'a man may write at any time, if he will set himself DOGGEDLY to it.' [Footnote: This word is commonly used to signify sullenly, gloomily and in that sense alone it appears in Dr Johnson's Dictionary. I suppose he meant by it 'with an OBSTINATE RESOLUTION, similar to that of a sullen man'.]