looping checkboxes not equal to zero in jquery

I have a set of checkboxes with class checkbox_item.I need to loop through all checkboxes which are not checked and their second part of splitted #ID value , ie $('.checkbox_item').prop('id').split('_')[1] should not be equal to zero

<input class="checkbox_item" id="414_0.5" type="checkbox">test
<input class="checkbox_item" id="415_1" type="checkbox">test1
<input class="checkbox_item" id="416_0.5" type="checkbox">test2
<input class="checkbox_item" id="417_0" type="checkbox">test3

My jquery function is as following:

 $('.checkbox_item').not(':checked').each(function(index,elem){
   /here I dont need checkboxes whose splitted #ID [1] not equals to zero
});

I have google it and couldn't find anything positive.Thanks in advance