You’ve got some sort of ruby version mixup here - you’ve got ruby 1.8.7 that is trying to load a native extension compiled for ruby 1.9. I’d guess that is because your shebang is saying use /usr/bin/ruby, which is presumably the system provided ruby, but dvm has setup the environment variables that ruby uses to have it look for gems in the rvm copy of ruby.
I assume that you can’t change the way it is invoked (to ruby process.rb rather than ./process.rb) but if you change the shebang to
#!/usr/bin/env ruby
that should pick up the rvm provided ruby, assuming that this script is running in a context where rvm has been loaded.