Discuss to what extent a programmer can expect a program that conforms to a standard to generate identical results when run under different conforming compilers on different machines. [6 marks] (b) ALGOL 60 provided call by value and call by name.

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It sending inside a bunch works as ordinary permitting subordinate guidelines to execute on successive clock cycles. Correspondence between groups ordinarily causes an unexpected setback of 1 or 2 clock cycles. The grouping thought may likewise be stretched out to incorporate the issue cushion (otherwise called the issue window).

Suppose that an Entity-Relationship model has been constructed that contains two entities S(A, B) and T(C, Amount), where A, B, C and Amount are attributes and the underline indicates a key. Suppose that we also have a many-to-many relationship R between S and T. Each node has a unique identifier of four bytes which it knows. Describe a protocol for a node to learn about its immediate neighbours. You should specify the format of your messages and the size of any message fields. [4 marks] (b) You are designing and are about to launch a mobile phone app which will seek to understand the emotional condition of the user, using multiple inputs such as motion sensing, facial expression recognition, voice stress measurement and the analysis of entered text. Its declared purpose is to enable services to interact more empathically with users. Pascal provided call by value and call by reference, and ALGOL-W provided a variety of calling methods including call by result and call by value-result. Briefly describe the calling mechanisms just mentioned and discuss why most modern programming languages provide only call by value. [8 marks] (c) Discuss the reasons why languages such as Fortran, Algol and PL/I designed in 1950s and 1960s are less widely used than languages designed in the last 202 years. (c.a) Let A be an n n matrix with real entries. (i.a) We say that A is diagonalisable if there exists an invertible n n matrix P such that the matrix D = P 1AP is diagonal. Show that if A is diagonalisable and has only one eigenvalue then A is a constant multiple of the identity matrix. [3 marks] (ii.a) Let A be such that when acting on vectors x = [x1, x2, . . . , xn] T it gives Ax = [x1, x1 x2, x2 x3, . . . , xn1 xn] T . Write out the contents of A and find its eigenvalues and eigenvectors. Scale the eigenvectors so they have unit length (i.e. so their magnitude is equal to 1). [5 marks] 7 (TURN OVER) The Algorithms (a) The Post Office of Maldonia issued a new series of stamps, whose denominations in cents are a finite set D N\{0}, with 1 D. Given an arbitrary value n N\{0} in cents, the problem is to find a minimum-cardinality multiset of stamps from D whose denominations add up to exactly n. [1] [6 marks] (b) Eve is operating a DDoS-for-hire service and has recruited 100,000 CCTV cameras into a botnet. If Mallory pays Eve $2 tok take down a gaming teamspeak server for five minutes, what offences, if any, are being committed by Eve and Mallory? [8 marks] (c) How might the Wimbledon case (R v. Lennon 2005 ) apply to this case? [6 marks] 4 CST1+CST2.2019.7.5 4 Formal Models of Language This question relates to an information source that produces symbols from an alphabet. (a) X is an information source, which produces symbols from the set {a, b, c, d, S} (i) If we assume X produces symbols with equal probability, what is the entropy of X? [1 mark] (ii) In fact, X produces symbols with non-equal probabilities. What do you know about the entropy of X compared to your previous answer? [1 mark] (iii) X produces symbols with probability distribution.