Differentiate among following: [at least 4 differences] 1. include and extended relation in use case diagram 2. Class and Object diagram

What precisely does "Identifier attribute" imply when it is used?

Suppose you are going to design an instant messaging application called Telegraph. Telegraph is a modularized application composed of UI module, Chat module, and Contact module. The UI module uses the Chat module and the Contact module to render the user interface. The Chat module deals with sending and receiving messages. The Chat module uses the Network module for network communication. When users send/receive messages via the network, the Chat module uses the Crypto module to encrypt/decrypt the message. The Contact module manages the contact list. It also uses the Crypto module for encryption/decryption. The Crypto module uses the Math module for calculation. Now we propose a metric to measure the stability of modules. Formally, we define the "stability" of a module i as Si = a+dut where di" (i.e., incoming connection or dependency) is the number of modules that directly or indirectly USES module i and d?ut (i.e., outgoing connection or dependency) is the number of modules that…

Write the command that can be used to perform the following:a. Back up the contents of the /var directory (which contains symbolically linked files)to the second nonrewinding SCSI tape device on the system using the tar utility.b. Append the file /etc/inittab to the archive created in Exercise 3a.c. Create a tarball called /stuff.tar.gz that contains all files in the /root/stuff directory. d.Use the cpio utility to back up all files in the /var directory (which contains symbolicallylinked files) to the first rewinding IDE tape device that has a block size of5KB.e. Perform a full filesystem backup of the /var filesystem using the dump utility andrecord the event in the /etc/dumpdates file.f. View the contents of the archives created in Exercises 3a, c, d, and e.g. Extract the contents of the archives created in Exercises 3a and c to the /rootdirectory.h. Extract the contents of the archives created in Exercises 3d and e to their originallocations.