ABSTRACT
Over the past twenty years, a new generation of computing applications has been silently entering our daily lives. RFID technology (Radio Frequency Identification) is used to track items within supply chains, computer-controlled actuator systems such as ABS (Anti-Blocking Systems) control the brakes of our cars, meetings and lectures are automatically recorded, most people carry integrated location and communication systems in the form of cell phones, and the list could continue. Computing technology is increasingly embedded in environments of human action, such as homes, transportation infrastructure, and consumer artifacts. In fact, without realizing it, we interact with hundreds if not thousands of computing devices throughout our daily activities. Moreover, these applications are increasingly networked through wired and wireless connections. Collectively referred to as ubiquitous computing (or ubicomp), these applications run continuously, unattended, and unsupervised (Weiser, 1993).
