I'm not sure why but it seems I've been targeted been down voting (I think by the same user) as it happened in all the questions I've asked in less than 60 seconds. I do not think this is due to the quality of the questions as they happened rather quickly? 

What should I do? I'm sorry if I've accidentally offended anyone. 

Questions I received down-votes on are:

https://mathoverflow.net/questions/306068/a-method-to-solve-discontinuous-differential-equations
https://mathoverflow.net/questions/301699/can-one-calculate-the-following-operator
https://mathoverflow.net/questions/304040/new-useful-method-for-summation-of-divergent-series
https://mathoverflow.net/questions/304853/why-does-this-pattern-emerge