WWW/Internet - Portal do Software Público Brasileiro

IADIS International Conference WWW/Internet 20102.3 Website and Database DesignThe website is an essential part of the implementation since every module that forms part of this system interactsin some way or another with the website. The website is not just an informative static website but afully fledged dynamic website which adapts and changes with the content input by the advertisers andsubscribers. It is also an informative website with a blog being continuously updated by the site administratoron news and information related to Location-based services from around the world.3. IMPLEMENTATIONA key difference between system implementation and all other phases of the lifecycle is that all activities upto this point have been performed in safe, protected and secure environments where issues that arose havelittle or no impact on the final system.3.1 WebsiteUsers have two different roles in the system, namely, subscriber advertiser. A registration module was requiredto distinguish between them. The website front-end can be accessed by anyone browsing the internetexcept for two specific pages being the Advertiser Page and the Subscriber Page.The advertising module allows advertisers to list advertisements on the website. This is divided into thelistings section and the add an advert section. The listing section displays all the adverts and correspondinginformation of the logged in advertiser whilst the add an advert section allows the advertiser to create advertisementsby choosing the location from the Google Map, category from the drop down list and fill in theadvertisement text.The subscriber module allows subscribers to set their user preferences on the system. Logged in subscriberscan choose categories pre-defined by the advertisers in order to receive adverts based on these categories.Subscribers are always presented with the list of subscribed categories which they can alter anytime theywant. Allowing users to choose the categories they are interested in makes the service more interesting.Both subscribers and advertisers can unsubscribe from the service from the website and all the related informationis permanently deleted. Other sections in the website like the blog section make the system morecomplete.3.2 Mobile ApplicationThe mobile application that was created is small service application that is used to get the subscriber’s mobileco-ordinates and send them to the system for the comparison with advertising zone areas. JAVA and variousBlackBerry API’s where used to develop this application. It consists of two basic screens which are the loginscreen and the status viewer screen. When the application is started, the Login Screen appears so that the subscriberinputs the username and password and then the application authenticates them with the system database.The application can then be minimized to run as a background process on the phone. Subscriber’s canalter the interval each time the co-ordinates are sent to the system database. This is done through the statusview screen. On this screen the viewer can also see the latest co-ordinates that had been sent to the systemdatabase.Since advertising zones are set by just a pair of co-ordinates we needed to find a way to know if the coordinatesbeing sent by the phone of the subscriber, fall in the advertising zone – the area around the pointsset by the advertiser. To do this we used the Haversin Formula (see Equation 1) which is an equation thatcalculates the distance and bearing between Latitude and Longitude points.Equation 1: Haversin Formula411