An app is offered to customers willing to install it on their…

Question Answered step-by-step An app is offered to customers willing to install it on their… An app is offered to customers willing to installit on their smartphone, which tracks customers’ location throughout the park anduses the phone accelerometer to monitor activity.(a) Describe how app developers could make sure the app delivers the best accuracyon location and activity tracking while preserving the phone battery as much aspossible through system and sensor sampling optimizations. [6 marks](b) A customer installs the app on their device. They have two other applicationson the phone which monitor their physical activity as well as their locationthroughout the day for clinical reasons. Describe how the phone operatingsystem could optimize the battery efficiency of the sensing across applications.[5 marks](c) A variety of wireless sensors are scattered throughout the park to monitorthe operation of the attractions by continuously gathering temporal data (e.g.,mechanical vibration, load, temperature, humidity).(i) Describe a combination of medium access and network layer protocols forinfrastructure-less multi-hop networks to aid the sensor data delivery tothe park management servers. Discuss advantages and disadvantages ofthe solution devised. [5 marks](ii) Describe a solution which uses protocols from the Internet of Things domainto offer a non multi-hop solution. Discuss the advantages and disadvantagesof the solution devised. [4 marks]10CST2.2018.8.1110 Principles of Communications(a) There are two main ways in which traffic sources can be controlled: open-loopand closed-loop. Describe the overall operation and use of these two kindsof network system: What are the key components of an open-loop controlledprotocol? What are the key components of a closed-loop, or feedback controlledsystem? What kinds of applications are suited to each class of control loop?[10 marks](b) Two important approaches to fairness are max-min, and proportional. Describewhat properties each of these offer, how they differ in how they can be used, andwhat happens in each case when demand exceeds supply of network capacity.[10 marks]11 (TURN OVER)CST2.2018.8.1211 Quantum Computing(a) In the quantum teleportation protocol, Alice and Bob are each in possession ofone qubit of a pair in the joint state ?12(|00i + |11i). In addition, Alice has aqubit in an arbitrary state |?i. Explain how the protocol works. In particular,show that it involves the transmission of exactly two classical bits of informationfrom Alice to Bob and demonstrate how, at the end of the protocol, Bob is inpossession of a qubit in state |?i. [10 marks](b) Suppose now that Alice has two qubits in a state|?i = ?0|00i + ?1|01i + ?2|10i + ?3|11i.In addition, there is a pair of qubits in the state ?12(|00i + |11i) such that Aliceis in possession of one qubit of the pair while Bob is in possession of the other.Alice now uses the quantum teleportation protocol to transmit to Bob the firstqubit of |?i. What is the resulting joint state of the two-qubit system composedof the second of Alice’s qubits and the qubit in Bob’s possession? [10 marks]12CST2.2018.8.1312 Security II(a) Name three different families of algebraic groups that are commonly used incryptographic applications of the Diffie-Hellman problem, where any groupelement (other than the neutral element) can be used as a generator. Brieflyoutline some of their main attributes, such as the set of elements and the groupoperator. [9 marks](b) You are preparing to participate in a password-cracking competition. Duringthe competition, you will be given the 128-bit hash-function output MD5(p).You have to find p, an 8-character password, each character having been chosenuniformly at random from a known alphabet of 64 ASCII characters.In the weeks preparing for the competition, you have access to a small clusterof GPU graphics cards that can evaluate MD5 109times per second.During the competition, you have only access to a laptop computer that canevaluate MD5 106times per second.Without any pre-computation, how long would it take to evaluate MD5 for allpossible passwords p in a brute-force attack(i) on the laptop? [2 marks](ii) on the GPU cluster? [2 marks]You decide to use the GPU cluster to pre-compute a rainbow table for thischallenge.(iii) What functions other than MD5 will the GPU cluster have to evaluate asoften as MD5 when building the rainbow table? [3 marks](iv) Your laptop has enough RAM for storing the rainbow table as a hash tableof 232 key-value pairs (x, y) with x, y ? {0, 1}128. If you execute MD5 250times while generating your rainbow table, how long will your laptop need(worst case) to find a password p stored in it, given its MD5 hash valueMD5(p)? Assume that the runtime is entirely dominated by the MD5evaluations (a) (i) Describe the difference between relevance feedback and query expansion interms of user interaction. [2 marks](ii) Explain what we mean by equivalence classing of terms and why it is useful.Give one example of equivalence classing that can fail to retrieve the rightdocuments. [2 marks](iii) Give an example of how asymmetric expansion of query terms can usefullymodel users’ expectations. Is asymmetric expansion of query terms moreor less efficient than equivalence classing? Justify your answer. [2 marks](iv) How would you evaluate an Information Retrieval task for which there ishigh tolerance for overlooked relevant information items? How might youmodify the F measure for such a task? Justify your answer. [3 marks](b) (i) Given the query “elvis music” and the following term frequencies for thethree documents doc1, doc2 and doc3 :elvis presley mississippi pop music lifedoc1 3 4 0 6 0 0doc2 4 0 4 0 0 3doc3 5 3 0 4 4 0calculate the cosine similarity between the query and each document (youcan ignore the idf term) in order to rank these documents in order ofrelevance. Show your workings. [2 marks](ii) The Rocchio algorithm is a classic algorithm for implementing relevancefeedback. Use Rocchio to compute the new query vector for “elvis music”using doc3 for relevance feedback (i.e., doc3 has been marked as relevant).Give suitable values for Rocchio’s weight parameters. As above, calculatecosine similarity (you can ignore the idf term) in order to rank thedocuments in order of relevance. Show your workings. [4 marks](iii) In Rocchio’s algorithm, positive feedback is typically more useful thannegative feedback. Give two example cases of negative documents beingfed back that can decrease the retrieval effectiveness of the Rocchiore-formulated query. Propose one way in which you can incorporatenegative feedback more effectively, and explain why this helps with thetwo examples you provided. Motivate your answer. [5 marks]8 Computer Science Engineering & Technology C++ Programming CMPE 127 Share QuestionEmailCopy link Comments (0)