A crew plays numerous seasons with 20 suits in every season. If the crew is at domestic, the opportunity of triumphing is zero.7. The probability of triumphing away is 0.4. No video games are attracts. Home and away video games typically exchange: ignoring the cease of the season, there may be a opportunity of 0.Seventy five that a domestic sport is observed by using an away game, and also a probability of 0.75 that an away game is observed by way of a home recreation. At the start of the season, there is an identical threat of a home or an away game. Show how this facts may be partially modelled as a Hidden Markov Model (HMM), treating home and away as hidden states. Give the parameters of the HMM. (b) What issue of the situation defined isn't efficiently blanketed with the aid of the HMM? (c) If the team's consequences are 'win, lose, win' on the start of the season, what probability estimate for 'home, away, home' is given by using this HMM? (d) You are given a entire file of person games, which include a document of the opponents. The win/loss ratio varies depending at the opponent. Explain how you can use such records to derive the parameters of a more complicated HMM (treating home and away as hidden states, as earlier than). (e) It is recommended that you could use an HMM to are expecting the results of subsequent season's video games, on the grounds that it's miles recognized who the opponent may be and whether or not the fit can be at domestic or away. How may you do that? How a success do you believe you studied this would be, compared to predicting whether a series of matches have been home or away based on a chain of match effects?

A social community can be represented as an undirected graph wherein vertexes constitute humans and edges represent bidirectional friendship relationships among human beings. A developer constructs a easy illustration of a social network the use of times of the subsequent Java magnificence: public class Person implements Serializable

private very last long accountId;

private String fullname; personal Set pals; public Person(String fullname) ... Public void addFriends(Set pals) ...

(a) The developer wishes to make certain that all public techniques for Person are thread-secure. Describe what thread-protection manner on this context. (b) Give a thread-safe implementation of the constructor for Person. You need to make sure no times of Person percentage the identical accountId. You might also create extra personal fields, techniques or internal lessons in Person. (c) Give a thread-secure implementation of add Friends which uses exceptional-grained locking to atomically set up new bidirectional friendship links between humans within the social community.

The company is willing to allow the installation of a pilot system so your approach can be evaluated under realistic conditions. Describe, in detail, your design for the evaluation: what data, operational conditions and aspects of your system would you consider, and why? What performance measures would you apply, and why? [10 marks] 5 Security "Robert Morris Senior was responsible for Unix security, Robert Morris Junior for the Internet worm. The father did much more damage to Internet security than the son" (Whitfield Diffie). Discuss. [20 marks]In programming languages in general, what is the difference between statically and dynamically-allocated variables? Without using the static keyword, give examples of both types of variable in the C language. [2 marks] (ii) What effect do the static and extern keywords have in C for both forms of variable

b) There are 32 characters in the ASCII set between 'A' and 'a'. All are printable. A potentially-infinite stream of 8-bit bytes can be made printable by encoding into base 32 and represented by a longer stream just using these characters. Give a syntactically-accurate definition in C for encode32(unsigned char a), called for each byte, which invokes putchar(char c) once or twice per call to render the encoded output. [5 marks] (c) Show how the for statement in C can be used to traverse a linked list. Explain the benefits of this coding style, mentioning whether the continue statement works appropriately. [4 marks] (d) type def char * mystring; mystring s201 = "201"; mystring s; A novice programmer writes the above code. What do you think they are intending to do and what two problems might they suffer? [2 marks] (e) An interpreter for a string processing language is written in C. Describe four storage and efficiency-related considerations when designing the module for storing strings for the interpreter?

Suppose that D is a domain and that lam : (D D) D and app : D (D D) are continuous functions. Using D, lam and app, you are required to give a denotational semantics to the terms of the untyped lambda calculus: M ::= x | x (M) | M M, where x ranges over some fixed, infinite set of variables and where terms are identified up to alpha-conversion. For each term M and list ~x = x1, . . . , xn of distinct variables containing the free variables of M, define a continuous function 7 [[~x ` M]]() mapping elements of the product domain Dn (regarded as functions from {x1, . . . , xn} to D) to elements of D. The definition should proceed by induction on the structure of M and you should state clearly, but without proof, any properties of continuous functions between domains which are needed for the definition to make sense. [10 marks] Show, by induction on the structure of M, that the following substitution property holds: [[~x ` M[M0 /x]]]() = [[~x, x ` M]]([x 7 [[~x ` M0 ]]()]). (You may assume without proof that [[~x, x ` M]]([x 7 d]) = [[~x ` M]]() when x does not occur free in M.) [5 marks] Show that if the composition app lam is the identity function on the function domain D D, then the denotational semantics respects beta-reduction, in the sense that [[~x ` ( x (M)) M0 ]]() = [[~x ` M[M0 /x]]](). [3 marks] What condition on lam and app will ensure that eta-reduction, x (Mx) M (where x is not free in M), is respected?

Consider the following code which takes an array d of n 32-bit integers and performs a bubble sort. for(i=0; id[j+1]) { t = d[j]; d[j] = d[j+1]; d[j+1] = t; } } (a) Given the following register allocation, how would the inner loop be encoded in assembler for a MIPS-32 style processor (i.e. a RISC machine with a load-store architecture and conditional branches being the only conditional instruction)? Assume that there are no delayed branches (unlike MIPS-32), do not unfold the loop and please do comment your code. register variable description r4 d base address of array d r5 m value of m r6 j register used to hold j r7 t register to hold temporary t [8 marks] (b) The classic 32-bit ARM instruction set makes every instruction conditional. How can your code make use of conditional instructions to reduce the number of data-dependent branches? [5 marks] (c) Given the classic 5-stage pipeline (below), how do the control and data hazards differ between your code in parts (a) and (b)? What is the impact on performance? [7 marks] instruction branch, decode execute memory write fetch & register read access b

How does the density of SIC machine code compare with current commercial processors? [2 marks] 3 Digital Communication I (a) Define the terms flat and hierarchical as applied to address spaces. [2 marks] (b) Give four examples of address spaces and state whether they are flat or hierarchical, and why. (c) Describe class-based addresses as used in the Internet. You need not worry about precise field sizes or class names. (d) Describe classless addresses as used in the Internet. (e) Why were they introduced? (f ) What information must be held in a routing table when classless addresses are used? (a) Define strong and weak consistency. (b) A process group manages a set of widely distributed replicas. The group is open and unstructured; that is, external processes may invoke any group member for reading or writing. (i) Discuss how the replicas can be kept strongly consistent in the presence of concurrent invocations and failures. (ii) Would it be more appropriate to use a structured group (with a single co-ordinator) to manage the replicas? Justify your answer. [6 marks] Your solution should discuss the selection and use of algorithms and protocols. It is not necessary to specify them in great detail. 5 Computer Graphics and Image Processing (a) We wish to produce two algorithms: one which draws the outline of a circle and one which draws a filled circle. (i) Describe an efficient algorithm which will draw a one-pixel wide outline of a circle of integer radius, R, centred on the origin. [10 marks] (ii) Describe the modifications required to your algorithm to make it draw a filled circle. [3 marks] (b) Given a function drawline(x1,y1,x2,y2), describe an algorithm for drawing a Bezier cubic curve to a specified level of accuracy using only straight lines.

(a) For random variables (RVs) A1, A2 and B, define what it means for A1 to be conditionally independent of A2 given B, written A1 A2|B. [1 mark] (b) Given mutually disjoint sets X1, X2 and Y of random variables from some Bayesian network, define what it means to say that a path from x1 X1 to x2 X2 is blocked by Y . [5 marks] (c) Given mutually disjoint sets X1, X2 and Y of random variables from some Bayesian network, define what it means for X1 and X2 to be d-separated by Y . What does this tell you about the probability distribution represented by the Bayesian network? [3 marks]

(e) Define how Bayesian networks and Markov random fields are used to represent probability distributions, and briefly describe the trade-offs involved in choosing one versus the other.

For each of the following, explain the difference between: (a) analogue computer and digital computer; [4 marks] (b) data-flow and control-flow model of computation; [4 marks] (c) little endian and big endian; [4 marks] (d) latency and bandwidth of data transmission; [4 marks] (e) spatial locality and temporal locality of data. [4 marks] 7 Operating System Foundations (a) Explain briefly the memory-management scheme of paging. [4 marks] (b) Give two disadvantages of paging. [2 marks] (c) A translation look-aside buffer (TLB) is sometimes used to optimise paging systems. Explain carefully how a TLB can be used in this way, and how it can optimise a paging system. [3 marks] (d) The fictional Letni 2P chip uses (single-level) paging and has a memory access time of 8 nanoseconds and a TLB search time of 2 nanoseconds. What hit ratio (the probability that an item is in the TLB) must be achieved if we require an average (paged) memory access time of 12 nanoseconds? [4 marks] (e) The management of the Letni Corporation wish you to design and evaluate a multi-level paging system for their new 64-bit processor, the 3P, which has 4K-sized pages. (i) Give details of your proposed multi-level paging system.

(a) Discuss the time and space complexity of dynamic programming algorithms in the context of sequence alignment problems. [6 marks] (b) Describe the differences between Soft and Hard Clustering. [6 marks] (c) Construct the de Bruijn graph of TACCTTCAGCGCCTTC by splitting it into k-mers for a suitable value of k. Comment on how the choice of k affects the construction. Discuss the use of de Bruijn graphs in the context of genome sequencing. [8 marks] 5 Business Studies (a) Describe five types of Intellectual Property. [5 marks] (b) Describe five topics that might be in a Market Requirements Document. [5 marks] (c) Giles Murchiston, a PhD student, has invented a new algorithm to control a dog walking robot. He realises that his algorithm may have wider applications including driverless cars, factory and farm robots, drones, and uses such as domestic robot lawnmowers or robot vacuum cleaners. Advise Giles on the exploitation of his idea.

Consider a programming language that consists of commands C composed from assignments V := E (where E is an expression) using sequences C1;C2, conditionals IF S THEN C1 ELSE C2 (where S is a statement) and while-loops WHILE S DO C. (a) Carefully explain the meaning of total correctness Hoare triples. [2 marks] (b) Suggest a command C such that the following partial correctness triple holds. {X = x} C {1 = 2} Explain why the triple holds. [4 marks] (c) Consider Hoare triples of the form {P} X := E {P[E/X]} where P, X and E range over formulas, variables and expressions, respectively. Recall that P[E/X] denotes P with E substituted for every occurrence of X in P. Write down an instance of such a triple that cannot be proved using Hoare logic and explain why it cannot be proved. [4 marks] (d) Write down a partial correctness specification for a command that adds the initial values stored in variables X and Y. The command should store the result in a variable Z. [4 marks]