diff --git a/AlgebraicDataflowArchitectureModel/models/SimpleUI.model b/AlgebraicDataflowArchitectureModel/models/SimpleUI.model
index 6aedfa6..6d4cb43 100644
--- a/AlgebraicDataflowArchitectureModel/models/SimpleUI.model
+++ b/AlgebraicDataflowArchitectureModel/models/SimpleUI.model
@@ -1,10 +1,10 @@
 init {
 	screenTemplates := {
-				"000": {"widgets": {"001": {"type": "textInput", "text": "", "visible": true}, 
-									"002": {"type": "button", "text": "Next", "visible": true}}, 
+				"000": {"widgets": {"001": {"type": "textInput", "text": "", "state": 0, "visible": true}, 
+									"002": {"type": "button", "text": "Next", "state": 0, "visible": true}}, 
 						"layout": true},
-				"001": {"widgets": {"003": {"type": "label", "text": "label", "visible": true}, 
-									"004": {"type": "button", "text": "Back", "visible": true}}, 
+				"001": {"widgets": {"003": {"type": "label", "text": "label", "state": 0, "visible": true}, 
+									"004": {"type": "button", "text": "Back", "state": 0, "visible": true}}, 
 						"layout": true}
 				}
 }
@@ -59,14 +59,20 @@
 	out screen(curS, transScreen(nextScId, screen)) = screen
 }
 
-channel EventHandler1(wid: Str) {
-	in screen.widgets.{wid="002"}.state(curState: Int, handleEvent1(nextState)) = nextState
-	out curScreen(curScId: Str, handleEvent1(nextState)) = if((curScId == "000") && (nextState == 0), "001", curScId)
+channel EventDispatch(wid: Str) {
+	in screen.widgets.{wid}.state(curState: Int, dispatchEvent(curScId, wid, nextState)) = nextState
+	ref curScreen(curScId: Str, dispatchEvent(curScId, wid, nextState))
+	out screenTemplates.{curScId}.widgets.{wid}.state(curState: Int, dispatchEvent(curScId, wid, nextState)) = nextState
 }
 
-channel EventHandler2(wid: Str) {
-	in screen.widgets.{wid="004"}.state(curState: Int, handleEvent2(nextState)) = nextState
-	out curScreen(curScId: Str, handleEvent2(nextState)) = if((curScId == "001") && (nextState == 0), "000", curScId)
+channel EventHandler1(scId: Str, wid: Str) {
+	in screenTemplates.{scId="000"}.widgets.{wid="002"}.state(curState: Int, handleEvent1(nextState)) = nextState
+	out curScreen(curScId: Str, handleEvent1(nextState)) = if(nextState == 0, "001", curScId)
+}
+ 
+channel EventHandler2(scId: Str, wid: Str) {
+	in screenTemplates.{scId="001"}.widgets.{wid="004"}.state(curState: Int, handleEvent2(nextState)) = nextState
+	out curScreen(curScId: Str, handleEvent2(nextState)) = if(nextState == 0, "000", curScId)
 }
 
 channel ChangeLayout {
diff --git a/AlgebraicDataflowArchitectureModel/src/models/dataConstraintModel/Channel.java b/AlgebraicDataflowArchitectureModel/src/models/dataConstraintModel/Channel.java
index 4e71af2..af144c8 100644
--- a/AlgebraicDataflowArchitectureModel/src/models/dataConstraintModel/Channel.java
+++ b/AlgebraicDataflowArchitectureModel/src/models/dataConstraintModel/Channel.java
@@ -110,6 +110,9 @@
 				channelMember.setOutside(true);
 			}
 		}
+		if (isNative) {
+			channelMember.getResource().getResourceHierarchy().setNative(true);
+		}
 	}
 	
 	public void removeChannelMember(ResourcePath res) {
@@ -128,6 +131,17 @@
 		}
 		return resources;
 	}
+
+	public boolean isNative() {
+		return isNative;
+	}
+
+	public void setNative(boolean isNative) {
+		this.isNative = isNative;
+		for (ChannelMember member: channelMembers) {
+			member.getResource().getResourceHierarchy().setNative(isNative);
+		}
+	}
 	
 	public String toString() {
 		return channelName;
@@ -143,12 +157,4 @@
 		}
 		return sourceText;
 	}
-
-	public boolean isNative() {
-		return isNative;
-	}
-
-	public void setNative(boolean isNative) {
-		this.isNative = isNative;
-	}
 }
diff --git a/AlgebraicDataflowArchitectureModel/src/models/dataConstraintModel/ResourceHierarchy.java b/AlgebraicDataflowArchitectureModel/src/models/dataConstraintModel/ResourceHierarchy.java
index b8a6fe3..9ce7e94 100644
--- a/AlgebraicDataflowArchitectureModel/src/models/dataConstraintModel/ResourceHierarchy.java
+++ b/AlgebraicDataflowArchitectureModel/src/models/dataConstraintModel/ResourceHierarchy.java
@@ -18,6 +18,7 @@
 	private int numParameters = 0;
 	protected Expression initialValue;
 	protected String initText;
+	protected boolean isNative = false;
 	
 	public ResourceHierarchy(String resourceName) {
 		this.parent = null;
@@ -211,6 +212,14 @@
 	public void setInitText(String initText) {
 		this.initText = initText;
 	}
+	 
+	public boolean isNative() {
+		return isNative;
+	}
+ 
+	public void setNative(boolean isNative) {
+		this.isNative = isNative;
+	}
 	
 	public String toString() {
 		if (parent == null) return resourceName;
diff --git a/AlgebraicDataflowArchitectureModel/src/simulator/Simulator.java b/AlgebraicDataflowArchitectureModel/src/simulator/Simulator.java
index 154a8a5..373fdfc 100644
--- a/AlgebraicDataflowArchitectureModel/src/simulator/Simulator.java
+++ b/AlgebraicDataflowArchitectureModel/src/simulator/Simulator.java
@@ -202,15 +202,22 @@
 				}
 				List<ResourceIdentifier> updatedOutResIds = nextSystemState.updateResourceState(outResId, outResVar[0], curResState, nextResState);
 				if (updatedOutResIds != null) {
-					Set<ResourceIdentifier> ancestors = new HashSet<>();
-					for (ResourceIdentifier updatedOutResId: updatedOutResIds) {
-						while (updatedOutResId != null && !ancestors.contains(updatedOutResId)) {		// In addition to the target state, its ancestors' states are also changed.
-							ancestors.add(updatedOutResId);
-							for (Event nextEvent: getNextEvents(updatedOutResId, curSystemState, nextSystemState)) {
-								fireEvent(nextEvent, curSystemState, nextSystemState);
+					if (out.getResource().getResourceHierarchy().isNative()) {
+						// For a native output resource, neither ancestor nor descendants are changed.
+						for (Event nextEvent: getNextEvents(outResId, curSystemState, nextSystemState)) {
+							fireEvent(nextEvent, curSystemState, nextSystemState);
+						}
+					} else {
+						// When a normal resource is updated.
+						Set<ResourceIdentifier> ancestors = new HashSet<>();
+						for (ResourceIdentifier updatedOutResId: updatedOutResIds) {
+							while (updatedOutResId != null && !ancestors.contains(updatedOutResId)) {		// In addition to the target state, its ancestors' states are also changed.
+								ancestors.add(updatedOutResId);
+								for (Event nextEvent: getNextEvents(updatedOutResId, curSystemState, nextSystemState)) {
+									fireEvent(nextEvent, curSystemState, nextSystemState);
+								}
+								updatedOutResId = (ResourceIdentifier) updatedOutResId.getParent();
 							}
-							if (channel.isNative()) break;		// To avoid multiple updates of the same resource.
-							updatedOutResId = (ResourceIdentifier) updatedOutResId.getParent();
 						}
 					}
 				}