Sampling and Reconstructing User Experience

The Experience Sampling and Reconstruction Method (ESRM) is a research method suitable for user studies conducted in situ that is needed for the design and evaluation of ambient intelligence technologies. ESRM is a diary method supported by a distributed application, Reconexp, which runs on a mobile device and a website, enabling surveying user attitudes, experiences, and requirements in field studies. ESRM combines aspects of the Experience Sampling Method and the Day Reconstruction Method aiming to reduce data loss, improve data quality, and reduce burden put upon participants. The authors present a case study of using this method in the context of a study of communication needs of working parents with young children. Requirements for future developments of the tool and the method are discussed.

A Petri-Net Based Context Representation in Smart Car Environment

Driving is a complex process influenced by a wide range of factors, especially complex interactions between the driver, the vehicle, and the environment. This paper represents the complex situations in smart car domain. Unlike existing context-aware systems which isolate one context situation from another, such as road congestion and car deceleration, this paper proposes a context model which considers the driver, vehicle and environment as a whole. The paper tries to discover the inherent relationship between the situations in the smart car environment, and proposes a context model to support the representation of situations and their correlation. The detailed example scenarios are given to illustrate our idea.

Threshold-Based Location-Aware Access Control

Designing a secure, resilient and user-friendly access control system is a challenging task. In this article, a threshold-based location-aware access control mechanism is proposed. This design uniquely combines the concepts of secret sharing and distance bounding protocols to tackle various security vulnerabilities. The proposed solution makes use of the fact that the user carries around various personal devices. This solution offers protection against any set of (t-1) or fewer compromised user’s devices, with t being an adjustable threshold number. It removes the single point of failure in the system, as access is granted when one carries any set of t user’s devices. Additionally it supports user-centered management, since users can alter the set of personal devices and can adjust the security parameters of the access control scheme towards their required level of security and reliability.

Tool-Supported User-Centred Prototyping of Mobile Applications

There is evidence that user-centred development increases the user-friendliness of resulting products and thus the distinguishing features compared to products of competitors. However, the user-centred development requires comprehensive software and usability engineering skills to keep the process both cost-effective and time-effective. This paper covers that problem and provides insights in so-called user-centred prototyping (UCP) tools which support the production of prototypes as well as their evaluation with end-users. In particular, UCP tool called MoPeDT (Pervasive Interface Development Toolkit for Mobile Phones) is introduced. It provides assistance to interface developers of applications where mobile phones are used as interaction devices to a user’s everyday pervasive environment. Based on found tool features for UCP tools, a feature study is described between related tools and MoPeDT as well as a comparative user study between this tool and a traditional approach. A further focus of the paper is the tool-supported execution of empiric evaluations.

Design and Implementation of Binary Tree Based Proactive Routing Protocols for Large MANETS

The Mobile Ad hoc Network (MANET) is a collection of connected mobile nodes without any centralized administration. Proactive routing approach is one of those categories of proposed routing protocol which is not suitable for larger network due to their high overhead to maintain routing table for each and every node. The novelty of this approach is to form a binary tree structure of several independent sub-networks by decomposing a large network to sub-networks. Each sub-network is monitored by an agent node which is selected by several broadcasted regulations. Agent node maintains two routing information; one for local routing within the sub-network and another for routing through all other agent node. In routing mechanism first source node checks for destination within sub-network then source sends destination address to respective parent agent node if destination is not available in local routing, this process follows up to the destination node using agent mode. This approach allowed any proactive routing protocol with scalability for every routing mechanism. The proposed approach is thoroughly analyzed and its justification for the connectivity through sub-networks, routing between each source to destination pair, scalability, etc., are given, which show expected performance.

Interactive Rendering of Indoor and Urban Environments on Handheld Devices by Combining Visibility Algorithms with Spatial Data Structures

This work presents a comparative study of various combinations of visibility algorithms (view-frustum culling, backface culling, and a simple yet fast algorithm called conservative backface culling) and different settings of standard spatial data structures (non-uniform Grids, BSP-Trees, Octrees, and Portal-Octrees) for enabling efficient graphics rendering of both indoor and urban 3D environments, especially suited for low-end handheld devices. Performance tests and analyses were conducted using two different mobile platforms and environments in the order of thousands of triangles. The authors demonstrate that navigation at interactive frame rates can be obtained using geometry rather than image-based rendering or point-based rendering on the cell phone Nokia n82.

A Generic Context Interpreter for Pervasive Context-Aware Systems

Developing pervasive context-aware systems to construct smart space applications has attracted much attention from researchers in recent decades. Although many different kinds of context-aware computing paradigms were built of late years, it is still a challenge for researchers to extend an existing system to different application domains and interoperate with other service systems due to heterogeneity among systems This paper proposes a generic context interpreter to overcome the dependency between context and hardware devices. The proposed generic context interpreter contains two modules: the context interpreter generator and the generic interpreter. The context interpreter generator imports sensor data from sensor devices as an XML schema and produces interpretation scripts instead of interpretation widgets. The generic interpreter generates the semantic context for context-aware applications. A context editor is also designed by employing schema matching algorithms for supporting context mapping between devices and context model.

DSOA

Ubiquitous environments are composed by a wide variety of devices, each one with different characteristics like communication protocol, programming and hardware platforms. These devices range from powerful equipment, like PCs, to limited ones, like cell phones, sensors, and actuators. The services provided by a ubiquitous environment rely on the interaction among devices. In order to support the development of applications in this context, the heterogeneity of communication protocols must be abstracted and the functionalities dynamically provided by devices should be easily available to application developers. This paper proposes a Device Service Oriented Architecture (DSOA) as an abstraction layer to help organize devices and its resources in a ubiquitous environment, while hiding details about communication protocols from developers. Based on DSOA, a lightweight middleware (uOS) and a high level protocol (uP) were developed. A use case is presented to illustrate the application of these concepts.

Security Assurance Evaluation and IT Systems’ Context of Use Security Criticality

Today’s IT systems are ubiquitous and take the form of small portable devices, to the convenience of the users. However, the reliance on this technology is increasing faster than the ability to deal with the simultaneously increasing threats to information security. This paper proposes metrics and a methodology for the evaluation of operational systems security assurance that take into account the measurement of security correctness of a safeguarding measure and the analysis of the security criticality of the context in which the system is operating (i.e., where is the system used and/or what for?). In that perspective, the paper also proposes a novel classification scheme for elucidating the security criticality level of an IT system. The advantage of this approach lies in the fact that the assurance level fluctuation based on the correctness of deployed security measures and the criticality of the context of use of the IT system or device, could provide guidance to users without security background on what activities they may or may not perform under certain circumstances. This work is illustrated with an application based on the case study of a Domain Name Server (DNS).

A 2D Barcode Validation System for Mobile Commerce

The wide deployment of wireless networks and mobile technologies and the significant increase in the number of mobile device users has created a very strong demand for emerging mobile commerce applications and services. Barcode-based identification and validation solutions are considered an important part of electronic commerce systems, particularly in electronic supply chain systems. This paper reports a mobile-based 2D barcode validation system as part of mobile commerce systems. This barcode-based validation solution is developed based on the Data Matrix 2D-Barcode standard to support barcode-based validation in mobile commerce systems on mobile devices. The paper demonstrates its application by building a mobile movie ticketing system.