train without pretrain weights。。。

I don't want to use the weight of the pre-training to train the model, where can I change；
I modified ：
# restorer, restore_ckpt = faster_rcnn.get_restorer()
# if not restorer is None:
# restorer.restore(sess, restore_ckpt)
# print('restore model')
added:
summary_writer = tf.summary.FileWriter(summary_path, graph=sess.graph)
saver = tf.train.Saver(max_to_keep=10)
But the result is not correct, no target can be predicted, and then the loss is also down.I look forward to your reply. Thank you. @yangxue0827 .