Question 1: Windows’ Ping sends four echo requests (i.e., four ping requests) to a target by default. Based on what you did in Activity 1 of Lab 4 and/or some of the information available in the Appendix of the Lab 4 assignment (i.e., the last pages in the Lab 4 assignment), which of the following is the appropriate command for pinging target 172.217.4.36 by sending 4 echo requests without changing any of the default pinging options?
Question 2: Based on what you did in Activity 1 of Lab 4 and/or some of the information available in the Appendix of the Lab 4 assignment (i.e., the last pages in the Lab 4 assignment), which of the following commands can you use to ping the target 172.217.4.36 repeatedly until you stop the pinging yourself?
Question 3: You start pinging with the option of repeatedly pinging a target. Based on what you did in Activity 1 of Lab 4 and/or some of the information available in the Appendix of the Lab 4 assignment (i.e., the last pages in the Lab 4 assignment), which of the following can you use to stop the pinging?
In: Computer Science
Delta Inc (DI), Elmo Trust (ET) and Frank Partnerships(FP) handle legal cases involving the breach of personal data under the Personal Data Protection Act (PDPA) on behalf of the Personal Data Protection Commission (PDPC). ET takes 20% of all suits in Singapore, FP handles 40% and DI takes the other 40% of cases. ET wins 70% of its cases for the suits by PDPC against businesses suspected of breach. FP wins 60% of its cases whilst DI wins only 40% of its cases.
a. Develop a probability tree showing all marginal, conditional, and joint probabilities.
b. Develop a joint probability table.
c. Using Bayes’ rule, determine the probability that the FP firm handled a particular case, given that the case was won.
In: Statistics and Probability
In: Computer Science
Let A and B be two stations attempting to transmit on an Ethernet. Each has a steady queue of frames ready to send; A’s frames will be numbered ?1, ?2 and so on, and B’s similarly. Let ? = 51.2 ???? be the exponential backoff base unit. Suppose A and B simultaneously attempt to send frame 1, collide, and happen to choose backoff times of 0 × ? and 1 × ?, respectively. As a result, Station A transmits ?1 while Station B waits. At the end of this transmission, B will attempt to retransmit ?1 while A will attempt to transmit ?2. These first attempts will collide, but now A backs off for either 0 × ? or 1 × ? (with equal probability), while B backs off for time equal to one of 0 × ?, 1 × ?, 2 × ? and 3× ? (with equal probability). (a) Give the probability that A wins this second backoff race immediately after his first collision. (b) Suppose A wins this second backoff race. A transmits ?2 and when it is finished, A and B collide again as A tries to transmit ?3 and B tries once more to transmit ?1. Give the probability that A wins this third backoff race immediately after the first collision. (c) What is the probability that A wins all the ? backoff races. (? is a given constant) (d) Assume that there are 3 stations sharing the Ethernet. Will the chance for A to win all the backoff races decrease or increase? Why?
In: Computer Science
In a dice game a player first rolls two dice. If the two numbers are l ≤ m then he wins if the third roll n has l≤n≤m. In words if he rolls a 5 and a 2, then he wins if the third roll is 2,3,4, or 5, while if he rolls two 4’s his only chance of winning is to roll another 4. What is the probability he wins?
In: Statistics and Probability
On each bet, a gambler loses $2 with probability 0.2, loses $1 with probability 0.7, or wins $10 with probability 0.1.
After 100 of these bets, what is the approximate probability that the gambler's total is negative?
Show your work below.
In: Statistics and Probability
1) Two teams, A and B, are playing a best of 5 game series. (The series is over once one team wins 3 games). The probability of A winning any given game is 0.6. Draw the tree diagram for all possible outcomes of the series.
2) List all possible combinations of rolling a 4-sided die (d4) and a 6-sided die (d6) (enumaration). Also determine the probability X {1..6} where X is the largest of the two numbers. Two players, A and B, are playing a game of dice. Player A rolls a d4 and a d6 and takes the largest of the two numbers (i.e. problem #2) Player B rolls a 6-sided die and adds one to the total. Player A wins on ties.
3) What is the conditional probability Player A wins given B's score is 3 (B rolled a 2)
4) What is the probability that player A will win any given game?
In: Statistics and Probability
The owner of a moving company usually has her most experienced manager predict the total number of labor hours required to complete a move. While useful, the owner is interested in a more accurate method of predicting the number of labor hours required. As a preliminary effort, data was collected on the number of work hours required to complete a move, number of cubic feet moved, the number of large pieces, and if an elevator was present.
How much correlation is there between the variables?
How much of the variability in strength is explained by the predictors?
Which of the predictor variables are significant at the 0.05 level?
At the 0.05 level of significance, what is the conclusion about the overall model hypothesis test?
What is the 90% confidence interval around the variable Elevator?
How are the degrees of freedom residuals computed?
At α = 0.001, is the overall model significant?
Estimate the number of hours required when 325 cubic feet are moved with 3 large pieces of furniture and no elevator is present.
Estimate the number of hours required when 425 cubic feet are moved with 7 large pieces of furniture and an elevator is present.
Estimate the number of hours required when 375 cubic feet are moved with 2 large pieces of furniture and no elevator is present.
| Hours | Feet | Large | Elevator |
| 24.00 | 545 | 3 | Yes |
| 13.50 | 400 | 2 | Yes |
| 26.25 | 562 | 2 | No |
| 25.00 | 540 | 2 | No |
| 9.00 | 220 | 1 | Yes |
| 20.00 | 344 | 3 | Yes |
| 22.00 | 569 | 2 | Yes |
| 11.25 | 340 | 1 | Yes |
| 50.00 | 900 | 6 | Yes |
| 12.00 | 285 | 1 | Yes |
| 38.75 | 865 | 4 | Yes |
| 40.00 | 831 | 4 | Yes |
| 19.50 | 344 | 3 | Yes |
| 18.00 | 360 | 2 | Yes |
| 28.00 | 750 | 3 | Yes |
| 27.00 | 650 | 2 | Yes |
| 21.00 | 415 | 2 | No |
| 15.00 | 275 | 2 | Yes |
| 25.00 | 557 | 2 | Yes |
| 45.00 | 1028 | 5 | Yes |
| 29.00 | 793 | 4 | Yes |
| 21.00 | 523 | 3 | Yes |
| 22.00 | 564 | 3 | Yes |
| 16.50 | 312 | 2 | Yes |
| 37.00 | 757 | 3 | No |
| 32.00 | 600 | 3 | No |
| 34.00 | 796 | 3 | Yes |
| 25.00 | 577 | 3 | Yes |
| 31.00 | 500 | 4 | Yes |
| 24.00 | 695 | 3 | Yes |
| 40.00 | 1054 | 4 | Yes |
| 27.00 | 486 | 3 | Yes |
| 18.00 | 442 | 2 | Yes |
| 62.50 | 1249 | 5 | No |
| 53.75 | 995 | 6 | Yes |
| 79.50 | 1397 | 7 | No |
In: Statistics and Probability
An elevator is hanging from a strong cable. The elevator is at rest. Compare the force exerted by the cable on the elevator to that exerted by the elevator on the cable. Also, compare the tension in the cable to the weight (mg) of the elevator.
The elevator begins accelerating upwards. Make the same comparisons.
The elevator begins descending at constant velocity. Make the same comparisons.
In: Physics
The project will study the coordination of multiple threads using semaphores.
The design should consist of two things:
(1) a list of every semaphore, its purpose, and its initial value, and
(2) pseudocode for each function. Code Your code should be nicely formatted with plenty of comments. The code should be easy to read, properly indented, employ good naming standards, good structure, and should correctly implement the design. Your code should match your pseudocode.
Project Language/Platform
This project must target a Unix platform and execute properly on our cs1 or csgrads1 Linux server.
The project must be written in Java. Elevator Simulation In this project threads are used to simulate people using an elevator to reach their floor.
The threads to be used are as follows: Person:
1) 49 people are in line at the elevator at the beginning of the simulation (1 thread per person).
2) Each person begins at floor 1.
3) Each person randomly picks a floor from 2 to 10.
4) A person will wait for an elevator to arrive at floor 1.
5) A person will board the elevator only if there is room.
6) Once at the destination floor, the person exits the elevator.
Elevator:
1) There is 1 elevator (1 thread for the elevator).
2) The elevator can only hold 7 people.
3) The elevator begins on floor 1.
4) The elevator leaves after the 7th person enters.
Main
1) Creates all threads and joins all person threads.
2) When last person reaches their floor, the simulation ends.
Other rules:
1) Each activity of each thread should be printed with identification (e.g., person 1).
2) A thread may not use sleeping as a means of coordinating with other threads.
3) Busy waiting (polling) is not allowed.
4) Mutual exclusion should be kept to a minimum to allow the most concurrency.
5) The semaphore value may not obtained and used as a basis for program logic.
6) All activities of a thread should only be output by that thread. Sample output:
Your project’s output should match the wording of the sample output:
Elevator door opens at floor 1
Person 0 enters elevator to go to floor 5
Person 1 enters elevator to go to floor 2
Person 2 enters elevator to go to floor 8
Person 3 enters elevator to go to floor 4
Person 4 enters elevator to go to floor 6
Person 5 enters elevator to go to floor 7
Person 6 enters elevator to go to floor 2
Elevator door closes
Elevator door opens at floor 2
Person 1 leaves elevator
Person 6 leaves elevator
Elevator door closes
Elevator door opens at floor 4
Person 3 leaves elevator
Elevator door closes
Elevator door opens at floor 5
Person 0 leaves elevator
Elevator door closes
Elevator door opens at floor 6
Person 4 leaves elevator
Elevator door closes
Elevator door opens at floor 7
Person 5 leaves elevator
Elevator door closes
Elevator door opens at floor 8
Person 2 leaves elevator
Elevator door closes
Elevator door opens at floor 1
…
Simulation done
In: Computer Science