memory leak fix

utils/utils.py

@@ -11,9 +11,9 @@ class Accumulator():
     def update(self, dict):
         for key in dict.keys():
             if key in self.dict.keys():
-                self.dict[key].append(dict[key])
+                self.dict[key].append(dict[key].detach().cpu().numpy())
             else:
-                self.dict[key] = [dict[key]]
+                self.dict[key] = [dict[key].detach().cpu().numpy()]
 
     def get(self):
         result = dict()