how to check checkbox whether true or false in angularjs using index value

repeat i have checkbox inside the repeat i want check wther checkbox is checked or not using their index value

html

 <div ng-repeat="Name in Names">

   <input type="checkbox"    ng-change="checkchange(BFMaterialStream.MaterialStream,$index)" 
 ng-model="Name.MaterialStream"  />
</div>

controller

$scope.checkchange=function(index){

      $scope.Names[index].active='true';
}

now i get correct value when i check the checkbox i have get active value is true but i have check means active should be change into false in my case it's true here i attached my code help how to do this..