In this provocative book, Barwise and Perry tackle the slippery subject of \"meaning, \" a subject that has long vexed linguists, language philosophers, and logicians.

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Situations and Attitudes.

Some patients, especially patients with chronic diseases such as heart disease, require continuous monitoring of their condition. Wearable devices for patient monitoring were introduced many years ago – for instance, wearable ambulatory ECG (electrocardiogram) recorders commonly known as Holter monitors (Figure 1) are used for monitoring cardiac patients. However, these monitors are quite bulky and can only record the signal for a limited time. Patients are often asked to wear a Holter monitor for a few days and then return to the clinic for diagnosis. This often overlooks transient but life-threatening events. In addition, we don’t know under what condition the signals are acquired, and this often leads to false alarms. For example, a sudden rise in heart rate may be caused by emotion, such as watching a horror movie, or by exercise, rather than by a heart condition. Body sensing To address these issues, the concept of Body Sensor Networks (BSN) was first proposed in 2002 by Prof. Guang-Zhong Yang from Imperial College London. The aim of the BSN is to provide a truly personalised monitoring platform that is pervasive, intelligent, and Figure 1 A patient wearing a Holter monitor

Body sensor networks

Sensor networks offer a powerful combination of distributed sensing, computing and communication. They lend themselves to countless applications and, at the same time, offer numerous challenges due to their peculiarities, primarily the stringent energy constraints to which sensing nodes are typically subjected. The distinguishing traits of sensor networks have a direct impact on the hardware design of the nodes at at least four levels: power source, processor, communication hardware, and sensors. Various hardware platforms have already been designed to test the many ideas spawned by the research community and to implement applications to virtually all fields of science and technology. We are convinced that CAS will be able to provide a substantial contribution to the development of this exciting field.

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Wireless sensor networks: applications and challenges of ubiquitous sensing

For wearable computing applications, human activity is a central part of the user’s context. In order to avoid user annoyance it should be acquired automatically using body-worn sensors. We propose to use multiple acceleration sensors that are distributed over the body, because they are lightweight, small and cheap. Furthermore activity can best be measured where it occurs. We present a hardware platform that we developed for the investigation of this issue and results as to where to place the sensors and how to extract the context information.

Multi-sensor Activity Context Detection for Wearable Computing

The broadcast and tetherless nature of wireless networks and the widespread deployment of Wi-Fi hotspots makes it easy to remotely locate a user by observing her wireless signals. Location is private information and can be used by malicious individuals for blackmail, stalking, and other privacy violations. In this paper, we analyze the problem of location privacy in wireless networks and present a protocol for improving location privacy. Our basic approach is to obfuscate several types of privacy-compromising information revealed by a mobile node, including sender identity, time of transmission, and signal strength. Our design is driven by real-system implementation and field experiments along with analysis and simulations. Our system allows users to choose the level of privacy they desire, thereby increasing the performance of less private users (while not sacrificing private users' privacy at the same time). We evaluated our system based on real-life mobility data and wireless LAN coverage. Our results show that a user of our system can be indistinguishable from a thousand users in the same coverage area.

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Preserving location privacy in wireless lans

Virtual Organizations enable new forms of collaboration for businesses in a networked society. During their formation business partners are selected on an as-needed basis. We consider the problem of using a reputation system to enhance the member selection in Virtual Organizations. The paper identifies the requirements for and the benefits of using a reputation system for this task. We identify attacks and analyze their impact and threat to using reputation systems. Based on these findings we propose the use of a specific model of reputation different from the prevalent models of reputation. The major contribution of this paper is an algorithm (called PathTrust) in this model that exploits the graph of relationships among the participants. It strongly emphasizes the transitive model of trust in a web of trust. We evaluate its performance, especially under attack, and show that it provides a clear advantage in the design of a Virtual Organization infrastructure.

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PathTrust: a trust-based reputation service for virtual organization formation

Ubicomp environments impose tough constraints on networks, including immediate communication, low energy consumption, minimal maintenance and administration. With the AwareCon network, we address these challenges by prescribing an integrated architecture that differs from classical networking, as it features an awareness of the surrounding situation and context. In various settings, where AwareCon was implemented on tiny battery driven devices, we show that applications and usability of devices benefit from this approach.

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AwareCon: Situation Aware Context Communication

More and more Ubiquitous computing scenarios arise where
computers are embedded into everyday objects as secondary
ariefacts. The need for a generic platform to enhance such
artifacts is addressed by the Smart-Its project. TecOs Smart-
Its are small-scale embedded computer devices that can be
easily attached to everyday objects and simply programmed for a
special task. Just like paper Post-Its are able to add some
information to an object a Smart-Its could add some computing,
perception and communication capability to an object. All this
capability was integrated into the tiny Smart-Its board itself
that is able to operate without any additional infrastructure.
This paper introduces the architecture of the Smart-Its
hardware, the design decisions for the hardware itself and
presents experiences we made while constructing and operating
these devices; some of these experience are also based on the
deployment and use of the first 160 Smart-Its devices.

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Smart-Its - communication and sensing technology for UbiComp environments

The issue we have focused on in the broad area of security for Pervasive Computing is maintaining trust in an interactive environment. Our solution is based on the premise that computers and implicit interaction mechanisms must function in accordance with the explicit parameters of physical human-human interaction. Otherwise, this results in imbalances between the physical and virtual worlds, which leads to ”windows of vulnerability”. Our solution presented requires an infrastructure of pervasive and context sensing technology, to provide entity mapping, policy and trust management services. We also investigate generating cryptographic keys using the context available The underlying technology is based on the Smart-Its context sensing, computation and communications platform.

/pdf/trust-context-spaces-an-infrastructure-for-pervasive-17kdrpjnyg.pdf

Philip Robinson

Papers

PathTrust: a trust-based reputation service for virtual organization formation

AwareCon: Situation Aware Context Communication

Smart-Its - communication and sensing technology for UbiComp environments

Trust Context Spaces: An Infrastructure for Pervasive Security in Context-Aware Environments

Security and Trust in IT Business Outsourcing: a Manifesto