diff --git a/Makefile b/Makefile
index e6f7a1d..3cc2ffa 100644
--- a/Makefile
+++ b/Makefile
@@ -73,12 +73,12 @@ all :
 .PHONY : clean
 clean:
 ifeq ($(OS_TYPE), WINDOWS)
-	del $(PROJECT).exe
+	del $(BUILD_DIR)/$(PROJECT).exe
 endif
 ifeq ($(OS_TYPE), LINUX)
-	rm $(PROJECT)
+	rm $(BUILD_DIR)/$(PROJECT)
 endif
 ifeq ($(OS_TYPE), OSX)
-	rm $(PROJECT)
+	rm $(BUILD_DIR)/$(PROJECT)
 endif
 	
diff --git a/core b/core
deleted file mode 100644
index 510b3e8..0000000
Binary files a/core and /dev/null differ
diff --git a/utilities/imp_util_ring_queue b/utilities/imp_util_ring_queue
index 19038b9..61a122b 160000
--- a/utilities/imp_util_ring_queue
+++ b/utilities/imp_util_ring_queue
@@ -1 +1 @@
-Subproject commit 19038b914b7d472556ab7e8445596a14d9fc038f
+Subproject commit 61a122b22be15ef94e2d114a819aee8fb7f39e0d