Given an "out" string length 4, such as "<<>>", and a word, return a new string where the word is in the middle of the out string, e. g. "<>". Note: use str. substring(i, j) to extract the String starting at index i and going up to but not including index j.

Consider a slotted aloha system, where the time slot equals the fixed duration of each packet. assume that there are 4 stations a,b,c,d sharing the medium. (a) stations a,b,c,d receive one packet each from higher layers at times 1.3, 1.5, 2.6,5.7 respectively. show which transmissions take place when, according to the slottedaloha protocol; describe all transmissions until all four packets have been successful.when needed, each station has access to the following sequence of random number, provided by a random number generator and drawn uniformly between 0 and 1: (1) station a draws numbers: 0.31, 0.27, 0.78, 0.9, 0.9, 0.11, 0. (2) station b draws numbers: 0.45, 0.28, 0.11, 0.83, 0.37, 0.22, 0. (3)station c draws numbers: 0.1, 0.2, 0.3, 0.4, 0. (4) station d draws numbers: 0.36, 0.77, 0.9, 0.1, 0.1, 0.1, 0.1, 0. (b) in slotted aloha, a station transmits in each time slot with a given probability. what probabilities would you assign to each of the four stations so as to: (i) maximize the efficiency of the protocol? (ii) maximize fairness among the four stations? (c) will the efficiency increase or decrease if we modify slotted aloha as follows: (i) get rid of slots and allow stations to transmit immediately? (ii) implement carrier sensing? (iii) implement collision detection? (iv) implement collision avoidance?

What statement best describes operating systems? it’s possible for modern computers to function without operating systems. most operating systems are free or very inexpensive. operating systems are managed by the computer’s microprocessor (cpu). operating systems manage the computer’s random access memory (ram).

In this lab, you complete a prewritten c program that calculates an employee’s productivity bonus and prints the employee’s name and bonus. bonuses are calculated based on an employee’s productivity score as shown below. a productivity score is calculated by first dividing an employee’s transactions dollar value by the number of transactions and then dividing the result by the number of shifts worked.