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Engineering : Electrical Engineering

Convolve the following two sequences

x(n) = ((1/3)^n) u(n) + ((1/2)^-n) u(-n-1), h(n) = (1/2)n u(n)

x(n) = ((1/3)^n) u(n) + ((1/2)^-n) u(-n-1), h(n) = (1/2)n u(n)

Engineering : Electrical Engineering

Find the Z-transform of these sequences. Clearly identify the ROC and

locate the poles and zeros.

a) x(n) = ((-1)^n) (2^-n)u(n)

b) x(n) = (1/2)^n.

c) x(n) = (-(1/2)^n) u(-n+2)

d) x(n) = (1/2)^n [u(n) – u(n-5)]

locate the poles and zeros.

a) x(n) = ((-1)^n) (2^-n)u(n)

b) x(n) = (1/2)^n.

c) x(n) = (-(1/2)^n) u(-n+2)

d) x(n) = (1/2)^n [u(n) – u(n-5)]

Engineering : Electrical Engineering

Seven terminals in an on-line system are attached to a communications line to the

central computer. Exactly four of these terminals are ready to transmit a

message. Assume that each terminal is equally likely to be in the ready state (i.e.

have a message to transmit). The central computer polls the terminals in a fixed

sequence without repetition. Let X be the # of terminals polled until the first

ready terminal is located (For example if the second terminal polled is ready,

then X=2, etc…)

a) Find the PMF (Probability Mass Function) of X

b) Find the mean and the Variance of X.

central computer. Exactly four of these terminals are ready to transmit a

message. Assume that each terminal is equally likely to be in the ready state (i.e.

have a message to transmit). The central computer polls the terminals in a fixed

sequence without repetition. Let X be the # of terminals polled until the first

ready terminal is located (For example if the second terminal polled is ready,

then X=2, etc…)

a) Find the PMF (Probability Mass Function) of X

b) Find the mean and the Variance of X.

Engineering : Electrical Engineering

A bowl contains 10 Red balls and B blue balls. 5 balls are selected at random

(without replacement). Let X be the number of blue balls selected. Find the

average value of X. Find the Variance of X. Now assume you select 5 balls with

replacement (i.e. you pick up a ball, note its color, and then put it back again). Find

E(X) and VAR (X) for this case.

(without replacement). Let X be the number of blue balls selected. Find the

average value of X. Find the Variance of X. Now assume you select 5 balls with

replacement (i.e. you pick up a ball, note its color, and then put it back again). Find

E(X) and VAR (X) for this case.

Engineering : Other

Two couples act on the beam as shown. If the magnitude of F is 350 lb, determine the resultant

couple moment.

couple moment.

Engineering : Chemical Engineering

An isothermal reversible reaction (A ↔ B) is carried out in an aqueous solution. The reaction is first-order in both directions. The forward rate constant is 1 h–1 and the equilibrium constant is 1. The feed to the plant contains 100 kg-mol/m3 of A and enters at the rate of 120 m3/h. The reactor is a stirred tank of volume 180 m3. The exit stream then goes to a separator, where the concentration of A (CA) is doubled and 30 m3/h is sent back to the CSTR in a continuous operation.

a. Find the conversion.

b. Compare this conversion with what you will get if there is no recycle.

a. Find the conversion.

b. Compare this conversion with what you will get if there is no recycle.

Engineering : Software Engineering

An event registration system for which the size is estimated at 190 KLOC is to be developed for an institution.The values of cost drivers are as follows:low reliability->0.78,high product complexity->1.15,experiance->1.13,hogh programming language experience->.85,other cost drivers assumed to be nominal->1.Compute the overall effort and schedule estimates.

Engineering : Mechanical Engineering

A regular hexagonal sheet of metal ABCDEF of 30 mm side, has its corner A on the HP and the side BC parallel to the HP.Draw the projections of the sheet when its plane is parallel to and 15 mm away from the VP?

Engineering : Mechanical Engineering

In a fluid scroll diode if the inlet is 20mm diameter, then the scroll will be 40mm radius (80mm diamater) as seen in several SAE papers. Why is that, and where does the 4:1 ratio come from? Thanks.

Engineering : Chemical Engineering

The inside of a baking oven is at a temperature of 177degrees celcius. The wall of an oven is made up of 4mm thick stainless steel of thermal conductivity 15.5W/mk. Determine the heat conduction heat loss per unit area from the oven if outside temperature is at 27degrees celcius above room temperature