diff --git a/README.md b/README.md
index d42577c..d6875ce 100644
--- a/README.md
+++ b/README.md
@@ -5,7 +5,7 @@
 3. [UAV Avoiding Dynamic Obstacles](https://github.com/hku-mars/dyn_small_obs_avoidance): One of the implementation of FAST-LIO in robot's planning.
 4. [R2LIVE](https://github.com/hku-mars/r2live): A high-precision LiDAR-inertial-Vision fusion work using FAST-LIO as LiDAR-inertial front-end.
 5. [UGV Demo](https://www.youtube.com/watch?v=wikgrQbE6Cs): Model Predictive Control for Trajectory Tracking on Differentiable Manifolds.
-6. [SC-A-LOAM](https://github.com/gisbi-kim/SC-A-LOAM#for-livox-lidar): A [Scan-Context](https://github.com/irapkaist/scancontext) loop closure module that can directly work with FAST-LIO.
+6. [FAST-LIO-SLAM](https://github.com/gisbi-kim/FAST_LIO_SLAM): The integration of FAST-LIO with [Scan-Context](https://github.com/irapkaist/scancontext) **loop closure** module.
 
 ## FAST-LIO
 **FAST-LIO** (Fast LiDAR-Inertial Odometry) is a computationally efficient and robust LiDAR-inertial odometry package. It fuses LiDAR feature points with IMU data using a tightly-coupled iterated extended Kalman filter to allow robust navigation in fast-motion, noisy or cluttered environments where degeneration occurs. Our package address many key issues:
@@ -21,7 +21,7 @@
 <img src="doc/ulhkwh_fastlio.gif" width = 49.6% >
 </div>
 
-**Related video:**  [FAST-LIO2](https://youtu.be/2OvjGnxszf8),  [FAST-LIO1](https://youtu.be/iYCY6T79oNU),  [FAST-LIO1 + Scan-context loop closure](https://youtu.be/Fw9S6D6HozA)
+**Related video:**  [FAST-LIO2](https://youtu.be/2OvjGnxszf8),  [FAST-LIO1](https://youtu.be/iYCY6T79oNU),  [FAST-LIO2 + Scan-context Loop Closure](https://www.youtube.com/watch?v=nu8j4yaBMnw)
 
 **Pipeline:**
 <div align="center">
diff --git a/src/laserMapping.cpp b/src/laserMapping.cpp
index 1ab6b0d..ffe592d 100644
--- a/src/laserMapping.cpp
+++ b/src/laserMapping.cpp
@@ -309,9 +309,9 @@ void livox_pcl_cbk(const livox_ros_driver::CustomMsg::ConstPtr &msg)
     }
     last_timestamp_lidar = msg->header.stamp.toSec();
     
-    if (!time_sync_en && abs(last_timestamp_imu - lidar_end_time) > 10.0)
+    if (!time_sync_en && abs(last_timestamp_imu - last_timestamp_lidar) > 10.0 && !imu_buffer.empty() && !lidar_buffer.empty() )
     {
-        printf("IMU and LiDAR not Synced, IMU time: %lf, lidar scan end time: %lf",last_timestamp_imu, lidar_end_time);
+        printf("IMU and LiDAR not Synced, IMU time: %lf, lidar header time: %lf \n",last_timestamp_imu, last_timestamp_lidar);
     }
 
     if (time_sync_en && !timediff_set_flg && abs(last_timestamp_lidar - last_timestamp_imu) > 1 && !imu_buffer.empty())