Still i am not satisfying with Logfile Shrinking in SQL Server?
In order for you to manage the transaction log  size of your database(s) which is in full recovery mode you should be taking regular and frequent transaction log backups. The frequency should be according to RPO and RTO defined

Do NOT change the recovery mode and shrink the log. You stated in your question that you didn't want any data loss by doing this you would lose point in time recovery. In the full recovery mode this is done by taking regular transaction log backups so that in the event of a failure, the backups can be used to restore the database to a point in time.

By changing the recovery mode, you are breaking the log chain which will prevent your ability to restore the database to a point in time.

Log backups will free space in the log by marking virtual log  inactive or reusable. This allows space within the log to be re-used and prevents growth (if the log is big enough initially). 

You should also be aware that putting the database in the simple recovery mode will not prevent any transaction log growth. The log will record all active transactions and will grow accordingly. The difference is that in the simple recovery model, the virtual log files are marked for re-use after a database checkpoint.

Here's a couple of links for more information on the transaction log:-

Overview of the transaction log:-  http://msdn.microsoft.com/en-us/library/ms190925.aspx
Transaction log backups:- http://msdn.microsoft.com/en-us/library/ms191429.aspx