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you can also make an applescript to do that and not require you to enter the admin password.
here is the script, just paste it in the script editor, change your admin password and save as an application.
To make sure that no one can read the content of the script and find out your password save it with the "run only" option also.
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do shell script "shutdown -r now" ¬
password "yourAdminPassword" with administrator privileges