Introduction

Imhotep is a part of the PIRAmIDE project which aims to ease the development of accessible and adaptable user interfaces. In order to do so, developers write code defining some preprocessor directives, taking into account both the user capabilities and the device characteristics. Then, applications can be uploaded to a repository. Finally, users will use an App Downloader to see the available applications and to download those applications compiled for them.

One of the most interesting things of Imhotep is the level of expressivity of the preprocessor directives. Developers can establish their own variables and rules such as:

IF screensize IS big AND resolution IS normal
THEN video IS high;
IF screensize IS big AND RESOLUTION IS big
THEN video IS very_high;

Where the variables, rules, and possible values of the variables are defined by the developer with the web based wizard. Furthermore, the concepts of resolution is big is created by the system taking into account the information of the mobile devices (provided by WURFL) and pondering it with their popularity (with Google Trends data).

You can find more detailed information in http://www.morelab.deusto.es/imhotep/.

Architecture

Imhotep is divided into 4 different modules:

• App downloader: users will install this application in their mobile device to connect to the repository and download adapted applications.
• The REST server: it contains the application repository. Once users select a desired application, the server will: * Use the Fuzzy Knowledge-Eliciting Reasoner to infer new values with the user and device configuration and the variables and rules established by the developer of the application. * Call the Preprocessor to select only the code that the final user requires. * Delegate the compilation of the application to the Compiler Manager. Currently the REST server only supports Android, but other compilers could be easily added. * Store the compiled application in the Compilation Cache, so future requests will not require to pass through the whole process if they have the same configuration values.
• Wizard: developers will use the wizard to establish the variables and the possible values of those variables. It uses the trends database to show the different values given a concrete user and a concrete device.
• Capacity Tester: users will need to create a user profile with their capabilities. Capacity Tester will gather those capabilities by testing them. Current application is just a proof of concept of how the Capacity Tester should work.

Wizard

The wizard is a web application that can be used by developers to play with the fuzzy values and create the proper profile and device configuration. It has been developed using Google Web Toolkit and it has been publicly deployed at:

• http://www.morelab.deusto.es/imhotep/wizard/

Preprocessor

The preprocessor directives define how the final source code must be generated, providing conditions for certain regions of code to be added or skipped, and adding Imhotep variables that the preprocessor will adapt for each compilation. The preprocessor identifies the directives when they start by //# in languages that support inline comments starting by //, such as Java, C# or C++, #// in languages that support inline comments starting by #, such as Python or Perl, and '// in VB.NET.

The preprocessor can avoid the compilation of fragments of code if certain conditions are matched. These conditions can include calls to functions provided by the system. Basic string and math functions are available, including lowercase, trim, contains, round or sqrt, as well as functions to check if a certain variable is available. The conditions can be embedded, as shown in the image below. The syntax of the conditions is based on the syntax used by the Python programming language.

Developers ask for user and device capabilities in these conditions. For example, one directive could state that if the user is blind the application should use a voice based interface. We have defined five categories for user capabilities that can be seen below:

Piramide Application Downloader

In order to download applications, a client is required. We provide the App downloader, an Android mobile application, which lets users select their profile (at the moment selecting among Regular or Blind, this part should be integrated with the Capacity Tester), and the URL of the REST Server (which defaults to our sample repository). With this information, the downloader shows the applications deployed in the remote repository and lets users select a version of an application and the application will be compiled in the server and downloaded and installed by the downloader.

Piramide REST Server

The PIRAmIDE REST Server is a servlet application that contains the repository of applications. Developers upload the applications to the repository, and users will get the adapted binaries. In order to deploy the PIRAmIDE REST Server, the PiramideRestServer?.war must be deployed, and the build.xml script in the deploy directory must be called.

Capacity Tester

The Capacity Tester is an Android application which is a proof of concept of how the Capacity Tester should work. In order to provide complex variables such as piramide.user.font.size.min, the application will show a text in different text sizes and the user will confirm if it can be read. In the same way, different combinations of colours can cause problems, so they are tested. In the future, other types of tests, for instance testing if the user can move the mobile device as expected, should be implemented.

Awards

• Aitor Almeida, Pablo Orduña, Eduardo Castillejo, Diego López-de-Ipiña. Assisted City. Best application in the Navigate, within the Via Inteligente awards for services oriented to citizens. Via Inteligente. March 7th, 2012. Link.

Publications

• Aitor Almeida, Pablo Orduña, Eduardo Castillejo, Diego López-de-Ipiña, Marcos Sacristan. A method for automatic generation of fuzzy membership functions for mobile device's characteristics based on Google Trends. Computers in Human Behaviour (Journal). Impact Factor (2011): 2.293 DOI: 10.1016/j.chb.2012.06.005. 2012. 2012.
• Aitor Almeida, Pablo Orduña, Eduardo Castillejo, Diego López-de-Ipiña, Marcos Sacristán. An approach to automatic generation of fuzzy membership functions using popularity metrics. 4th World Summit on the Knowledge Society. Mykonos, Greece, September, 2011.
• Aitor Almeida, Pablo Orduña, Eduardo Castillejo, Diego López-de-Ipiña, Marcos Sacristán. Adaptative applications for heterogeneous intelligent environments. ICOST 2011: 9th International Conference on Smart Homes and Health Telematics. Montréal, Canada, June 2011. LNCS6719, Toward Useful Services for Elderly and People with Disabilities, Springer, ISBN: 978-3-642-21534-6, pp. 1-8
• Aitor Almeida, Pablo Orduña, Eduardo Castillejo, Diego Lopez-de-Ipiña, Marcos Sacristan. Imhotep: an approach to user and device conscious mobile applications Personal and Ubiquitous Computing (Journal). Springer. Impact Factor (2009): 1.554. ISSN: 1617-4909. DOI: 10.1007/s00779-010-0359-8. January 2011.
• Aitor Almeida, Pablo Orduña, Eduardo Castillejo, Diego Lopez-de-Ipiña, Marcos Sacristan. A user-centric approach to adaptable mobile interfaces. Actas del II International Workshop of Ambient Assisted Living (IWAAL 2010), p.p. 153-160 Valencia, Spain, September 7-10, 2010 (ISBN: 978-84-92812-67-7)

Acknowledgments

This work has been supported by project grant TSI-020301-2008-2 (PIRAmIDE), funded by the Spanish Ministerio de Industria, Turismo y Comercio).

Authors would also like to acknowledge the work of the Open Source software used on top of which this project was developed:

• jFuzzyLogic
• ZXing
• WURFL
• Jython
• Google Web Toolkit
• RESTlet
• Android
• Python
• MySQL
• Java

As well as other projects and services, such as

• Google Trends