Canonical Forms and Standard Forms

Standard Forms

• each term in the function can have any number of literals.

Example, F1 = a +b’c + cde

• There are 5 variables in F1 (a,b,c,d,e)
• Canonical form terms should be written as m0, m1… (sum of Products) or M0, M1, M2… (Product of sums).
• Each term in the canonical form should have all the literals.

Example: F1 = ab’c’d’e’ + abcd’e’ + abcde

Minterms

• It is Sum of Products
• Canonical form is Sum of Minterms
• three variable minterms are shown below
 x a b c minterms 0 0 0 0 m0=a’.b’.c’ 1 0 0 1 m1=a’.b’.c 2 0 1 0 m2=a’.b.c’ 3 0 1 1 m3=a’.b.c 4 1 0 0 m4=a.b’.c’ 5 1 0 1 m5=a.b’.c 6 1 1 0 m6=a.b.c’ 7 1 1 1 m7=a.b.c

Maxterms

• Product of Sum (PoS)
• Canonical form is Product of MaxTerms
• three variable maxterms are shown below
 x a b c minterms 0 0 0 0 M0=(a+b+c) 1 0 0 1 M1=(a+b+c’) 2 0 1 0 M2=(a+b’+c) 3 0 1 1 M3=(a+b’+c’) 4 1 0 0 M4=(a’+b+c) 5 1 0 1 M5=(a’+b+c’) 6 1 1 0 M6=(a’+b’+c) 7 1 1 1 M7=(a’+b’+c’)

usually

 Mi = (mj)’

Express the boolean function F = A + BC in a sum of minterms.

The function has three variables,

so F = A + BC will be

F = A(B + B’) + (A +A’) BC  [since, x + x’ =1]

F = AB + AB’ + ABC + A’BC

F = AB(C+C’) + AB’(C+C’) + ABC + A’BC

F = ABC + ABC’ + AB’C + AB’C’ + ABC + A’BC

F = ABC + ABC’ + AB’C + AB’C’ + A’BC [since x + x = x]

F= m0 + m6 + m5 + m4 + m3

Implementing a new system call in Kernel version 2.6.32

A system call is used by application or user programs to request service from the operating systems. Since the user programs does not have direct access to the kernel whereas the OS has the direct access. OS can access the hardware through system calls only. The following files has to be modified for implementing a system call /usr/src/linux-2.6.32.5/arch/x86/kernel/syscall_table_32.S /usr/src/linux-2.6.32.5/arch/x86/include/asm/unistd_32.h /usr/src/linux-2.6.32.5/include/linux/syscalls.h /usr/src/linux-2.6.32.5/Makefile New set of files to be created Create a new directory newcall/ inside the path “ /usr/src/linux-2.6.32.5/ ” Create new files Makefile, newcall.c and put them in the /usr/src/linux-2.6.32.5/newcall/ folder Create new user files (in any folder of Linux) to test the system call testnewcall.c, testnewcall.h (created in /home/pradeepkumar ) syscall_table_32.S Find the file /usr/src/linux-2.6.32.5/arch/x86/kernel/syscall_tab

How to Access MOODLE in Intranet and Internet

When Moodle is accessed either in Intranet or internet, there will not be any issue. But occasions when the MOODLE Site has to be accessed both in the intranet and in the Internet, here is a simple trick Server Used: IBM Blade Servers Operating system: Windows Server 2008 Moodle Version: 2.4 WAMP Server is used. Number of Users: 3000 (Students) + 200 (Faculty) Open the config.php from ~/moodle/config.php include these lines \$CFG->wwwroot = 'http://'.\$server_id.'/vitcc'; \$CFG->dataroot  = 'C:\\wamp\\moodledata'; before the following line \$CFG->directorypermissions = 07xx; Restart the WAMP Server and you can Check MOODLE Site both in Internet and Intranet. The above Image tells the intranet Link and the internet link can be opened outside the campus network

Electrical Machine Design (equations)

Factors DC Machine Transformers Induction Machines Synchronous Machines Output Equation P a =C o D 2 Ln, where Pa=P/h for generators, Pa=P for motors For Single Phase Q=2.22 f B m A i K w A w d 10 -3 For Three Phase Q=3.33 f B m A i K w A w d 10 -3 Q=C o D 2 L n s KVA Input Q= HP * 0.746 / Cos f * h Q=C o D 2 L n s KVA Input Q= HP * 0.746 / Cos f * h For Turbo alternators Q=1.11B av ac K ws V a 2 L 10 -3 /n s Output Coefficient C o =B av ac* 10 -3 where Bav-magnetic loading and ac - electric loading DNA C o =11 K ws B av ac 10 -3 C o =11 K ws B av ac 10 -3 Choice of Magnetic Loading Flux Density in Teeth Frequency of Flux Reversals Size of machine DNA Magnetizing current, Flux Density, Iron loss Iron loss, Stability, Voltage Rating, Parallel Operation, Transient ShortCircuit current