Consider the following statements regarding how government spending responds to changes in aggregate income, wealth, and interest rates.

A. Government spending responds directly to changes in aggregate income, wealth, and interest rates. Changes in aggregate income, wealth, and interest rates automatically cause government spending to change.

B. Government spending does not respond directly or indirectly to changes in aggregate income, wealth, or interest rates. Changes in aggregate income, wealth, and interest rates do not have any effect on government spending.

C. Government spending responds indirectly to changes in aggregate income, wealth, or interest rates. During a recession, aggregate income and wealth will fall and the government may decide to increase government spending to stimulate output and jobs in the economy.

Which of the statements are true?

Statements A and B

Statement C

Statement A

Statement B

The data in the accompanying table represent the rate of return of a certain company stock for 11 months, compared with the rate of return of a certain index of 500 stocks. Both are in percent. Test if there is a positive relationship at the α=0.01 level of significance.

• What is the Standard Error of the regression?

• What is the left boundary of the estimation of the regression equation slope?

• What is the critical value of the test?   

• What is the test statistics of the test?

• What is the p-value of the test?

Conduct a test and find if there is a difference at the α=0.01 level of significance. In​randomized, double-blind clinical trials of a new vaccine, children were randomly divided into two groups. Subjects in group 1 received the new vaccine while subjects in group 2 received a control vaccine. After the first dose, 67 of 607 subjects in the experimental group (group 1) experienced fever as a side effect. After the first dose, 109 of 728 subjects in the control group​ (group 2) experienced fever as a side effect.

A. Construct the null hypothesis and the alternative hypothesis.

B. What is the P-value of the test result?

C. What is the test statistics?

D. What is the positive value of the critical value?

E. Do we have enough evidence to reject the null hypothesis?

F. What is the test conclusion?

G. What is the upper boundary of the 99% Confidence Interval of p1-p2?

In quantum chromodynamics, long flux tubes will always snap because a quark-antiquark pair gets created from the vacuum, and hadronization results with a quark attached to each new end.

In string theory, if we try to stretch a single string out a long distance, will it also snap? If open strings with Neumann boundary conditions are allowed, this can always happen. Suppose this is not the case. If D0-branes exist, we can create a pair of them from the vacuum, and the string will still snap. Even if no D0-branes don't exist, or space filling branes either, as long as we have some Dp-brane for some p in between, the Dp-brane can be wrapped up as finite closed bubble, and we can create a pair of such bubbles. The string will still snap into "tadpoles".

In some string theories, strings carry charges and are BPS states. Can they snap? I doubt it.

1. Consider a simplified one-dimensional laminar flame, such as that discussed in the classroom. The earliest description of a laminar flame is that of Mallard and Le Chatelier in 1883. Assume that:

a. 1-D, constant area, steady flow,

b. kinetic and potential energies, viscous shear work, and thermal

radiation are neglected,

c. pressure is constant,

d. diffusion of heat and mass are governed by Fourier’s and Fick’s laws

and binary diffusion is applied,

e. Lewis number is unity,

f. individual specific heats are all equal and constant,

g. fuel and oxidizer form products in a single-step exothermic reaction,

h. fuel is completely consumed at the flame with oxidizer in

stoichiometric or excess proportion.

By applying suitable boundary conditions, please derive the expressions for laminar flame velocity and flame thickness. (Simplified solution can be found in most of the combustion textbook, such as the one by S.R. Turns(1996) or the one by I. Glassman (1993 or newer edition).)

Fundamental of power electronics:

In a certain application, an unregulated dc input voltage can vary between 18 and 36 V. It is desired to produce a regulated output of 28 V to supply a 2 A load. control circuit automatically adjust D to maintain the constant output voltage and current. All ideal components.  Hence, a converter is needed that is capable of both increasing and decreasing the voltage. Since the input and output voltages are both positive, converters that invert the voltage polarity (such as the basic buck-boost converter) are not suited for this application.

(1) Sketch the waveforms of the transistor voltage Vds and transistor current IT or (Id for drain current) and give expressions for their peak values. find the numerical maximum value on the sketch for Vds and IT (Id). ignore the effect ripple.

(2) Derive the expression for switching frequency at the converter operates between the CCM and DCM at the boundary. the answer is in term of D, Vin, L1, L2, iL1, iL2. you may assume L1=L2.

Match the organelle to its function.
Smooth Endoplasmic Reticulum
Rough Endoplasmic Reticulum
Golgi Apparatus
Plasma Membrane
Chloroplast
Mitochondrion
Lysosome
Centriole
Nucleolus
Nucleus
Cytoskeleton

A. Refining, tagging, sorting, and packaging proteins. Sends completed proteins to their final locations.

B. Studded with ribosomes. Sends polypeptides to Golgi.

C. Lipid synthesis and detoxification functions.

D. Contains all genetic information for the cell (Chromatin)

E. Microtubule (protein) scaffolding throughout the cell. Structural support, movement, transportation.

F. Contains genes for making ribosome parts.

G. Contains enzymes to break down large food molecules and damaged organelles.

H. Involved in the formation of mitotic spindle for cell division. Helps guide the separation of chromosomes. I.
Stores/Converts solar energy to chemical energy in sugars.

J. Selectively permeable boundary for all cells.

K. Transfers chemical energy from organic molecules to ATP.

A consulting firm hired you to improve the network security of a Hospital by adding extra services for defence against external attacks.

1. In order to protect classified encrypted data from disclosure and transmission outside of the Hospital network, you need to choose among the following: proper configuration of DMZ, use of strong encryption algorithms, safeguards over keys. State your selection and justify your choice.

2. You want to use a packet firewall to protect the Hospital network but you are hesitant to choose the right location among the following: putting it on the web server at DMZ, putting it along with the IDS server, putting it on the screened subnet with DMZ, or putting it on the domain boundary. Recommend the right answer with justification as to why or why not.

3. Which one of the following can be used to protect a network against unauthorised external connections: VLAN, strong authentication, or an access control list of trusted devices? Justify your answer

A consulting firm hired you to improve the network security of a Hospital by adding extra services for defence against external attacks.

1. In order to protect classified encrypted data from disclosure and transmission outside of the Hospital network, you need to choose among the following: proper configuration of DMZ, use of strong encryption algorithms, safeguards over keys. State your selection and justify your choice.

2. You want to use a packet firewall to protect the Hospital network but you are hesitant to choose the right location among the following: putting it on the web server at DMZ, putting it along with the IDS server, putting it on the screened subnet with DMZ, or putting it on the domain boundary. Recommend the right answer with justification as to why or why not.

3. Which one of the following can be used to protect a network against unauthorised external connections: VLAN, strong authentication, or an access control list of trusted devices? Justify your answer.