turn over CO639/2020 UNIVERSITY OF KENT FACULTY OF SCIENCES LEVEL 6 EXAMINATION SCHOOL OF COMPUTING Electronic Commerce Two hours The paper contains THREE questions. Answer ALL the questions. – 2 – 1. (a) Use the following PHP script to demonstrate why the content is dynamic. if(date(“a”) == “am”) echo “Good morning”; else echo “Good afternoon”; ?> [2 marks] (b) Elaborate why dynamic content is important to e-Commerce. [3 marks] (c) Elaborate the PHP communication by providing more details of each numbered step in the following University of Kent deployment. [5 marks] (d) Ordering music items from an on-line store starts with a customer first browsing the catalogue, selecting the music items to order and then submitting the order. This is followed by entering the payment details, which are subject to validation. If validation fails a message is displayed to indicate that payment was unsuccessful and the order transaction is cancelled. Otherwise the payment is deducted from the account, the items delivered and a receipt is sent by email. (i) Design a software structure for this system. Specify the functions that you need to implement for each functionality of this system. [4 marks] – 3 – turn over (ii) Consider a function that allows a customer to browse the catalogue and add items to the shopping cart. Write an outline of PHP pseudo-code (that does not have to be grammatically strict and correct) that implements this function. State any assumptions you have made, for example, that the user has already been authenticated, etc. [6 marks] 2. Using the following PHP script to demonstrate how the server-side session file works together with the client-side cookie. Draw a schematic diagram in your answer. Your answer should also include the confidentiality issue. session_start(); if(isset($_SESSION[‘count’])) $count = ++$_SESSION[‘count’]; else $count = $_SESSION[‘count’] = 1; echo “You’ve visited this page {$count} times”; ?> [20 marks] 3. Assume a service has a predictable daily demand where the peak requires 500 servers at noon but the trough requires only 100 servers at midnight, as shown in Figure 1. Figure 1 (a) If the average use over a whole day is 300 servers, calculate the server hours over the whole day (shaded area under the curve); [2 marks] (b) Calculate the actual utilisation; [3 marks] (c) Elaborate whether you recommend the service provider to move to the cloud based on the above calculation; [5 marks] (d) Explain which are the key features of Cloud Computing exploited by this example. [10 marks]
