Mobile and Semantic Web-Based Delivery of Context-Aware Information and Services in Construction - Mobile and Pervasive Computing in Construction - page 14

several tasks and projects at the same time. These include real-time progress
monitoring of on-site works, remote expert support, on-site collection of qual-
itative and quantitative measurements, collaborative review of technical drawings,
on-site supplier and subcontractor evaluation, on-site evaluation of equipment
usage measurements, keeping track of the physical equipment position anytime and
anywhere, answering audit checklists and filing audit reports during site audits
(Meissner et al ., 2001). Very often the urgency of the situation does not allow
enough time to search for the relevant information. Keeping track of all the tasks
and related dependencies has become a formidable challenge. The application of
technology to address such issues remains limited. Also, given the limitations of
mobile devices (such as limited display size, limited battery power, storage capacity,
low processing power, uncomfortable data input methods), undertaking such
information search is even more difficult. All these point to the need for semantic
awareness, in order to help mobile workers (or computer programs) find the
relevant information suited to the workers' context.
An approach to overcoming the above limitations is through the development
of push-based services, which are complementary to the existing pull-based
services (Anumba et al ., 2005). In a typical knowledge/document sharing envi-
ronment the end user has to seek the documents to perform tasks. For this, the user
may need to share documents, navigate and query the document database as
shown in Figure 2.1. Current document sharing systems consist of a set of pull
services (i.e. users actively seeking information, and they need to go and get what
they actually need). What is required besides these pull services are push-based
services that provide the required information to the end user based on their
current context.
It is a requirement of knowledge management tools to give users the ability to
organize information into a controllable asset. Building an Intranet/Internet-based
Figure 2.1 The concept of push-based services