public void finalize() {
		active = false;
		INSTANCE = null;
		SensorBus.getInstance().unsubscribe(this);
		if(featureRunner!= null && featureRunner.isAlive()) {
			featureRunner.stop();
		}
		featureRunner= null;
		
		Log.d(TAG, "Destroyed FeatureCalculation");
	}
	private FeatureCalculation() {
		active = true;
		SensorBus.getInstance().subscribe(this);
	}