Catálogo de publicaciones - libros

Extensive educational research discusses the potential for information and communication technologies in supporting homework, but most has focused on providing content. The research in this paper focuses instead on the issues around managing homework and balancing home and school through the capabilities of ubiquitous technologies. As part of our requirements capture we presented three families with demonstrators of ubiquitous computing systems. Our technologies provoked reactions to situated and embedded information capture and access, and locational information capture through mobile devices. The subtlety and complexity of roles and relationships of different family members raised issues around trust and privacy in relation to children’s homework practices. We consider how these drove acceptance of the technologies, and how the contrasts between family and educational relationships produced different requirements for technologies managing information transfer inside and outside the home. Overall, we highlight how respect for these concerns can inform the design of pervasive technologies, particularly within the domestic and educational contexts bridged.

Mobile phones are increasingly becoming ubiquitous computational devices that are almost always available, individually adaptable, and nearly universally connectable (using both wide area and short range communication capabilities). Until -like speech interfaces are fully developed, mobile phones seem thus poised to become our main devices for interacting with intelligent spaces and smart appliances, such as buying train passes, operating vending machines, or controlling smart homes (e.g., TVs, stereos, and dishwashers, as well as heating and light). But how much can a mobile phone simplify our everyday interactions, before it itself becomes a usability burden? What are the capabilities and limitations of using mobile phones to control smart , i.e., operating things like ATMs or coffee makers that typically do not benefit from remote control? This paper presents a user study investigating the use of a prototypical, mobile phone based interaction system to operate a range of appliances in a number of different task settings. Our results show that mobile devices can greatly simplify appliance operation in exceptional situations, but that the idea of a universal interaction device is less suited for general, everyday appliance control.

We report a qualitative study of the use of physical space and wireless laptops by ten United States households. Although wireless laptops purportedly offer the opportunity and affordances to go “anywhere in the home,” laptops were generally used in a small set of particular places rather than moving fluidly through the home: wireless laptops were portable, but not mobile We present factors that influence laptop movement in the home. We also present a model of people’s use of space in the home, identifying a small set of favored places of long-term use and a larger set of kinetic places used for specific tasks. We discuss how the factors we have identified generally promote use of laptops in favored places and generally discourage use of laptops in kinetic places. We discuss how our findings are relevant to the design of technologies for the home.

Wireless phones and text messaging are tremendously popular in many areas of society. However, they are still relatively unused in hospitals where pagers are a pervasive communication device that is notoriously difficult to replace. This paper studies pager and wireless phone use at the oncology department at University Hospital of North Norway. Participatory observation and interviews with physicians are used to provide qualitative analysis about the use, drawbacks and benefits of both technologies. A number of important issues are addressed that should aid designers of next generation mobile communication systems for hospitals. In particular, the data points towards specific features that will be crucial for the overall usability and acceptance of an integrated device that supports paging, voice and text services. Of particular importance will be features that allow users to manage their communication availability and avoid interruptions.

Ground reaction forces generated during normal walking have recently been used to identify and/or classify individuals based upon the pattern of the forces observed over time. One feature that can be extracted from vertical ground reaction forces is body mass. This single feature has identifying power comparable to other studies that use multiple and more complex features. This study contributes to understanding the role of body mass in identification by (1) quantifying the accuracy and precision with which body mass can be obtained using vertical ground reaction forces, (2) quantifying the distribution of body mass across a population larger than has previously been studied in relation to gait analysis, and (3) quantifying the expected identification capabilities of systems using body mass as a weak biometric. Our results show that body mass can be measured in a fraction of a second with less than a 1 kilogram standard deviation of error.

The retail industry, which is characterized by highly complex supply chain processes, still faces stockout rates of 5-10%. This results in sales losses of up to 4% which corresponds to hundreds of millions of dollars for large retailers. The most significant cause for stockout situations is inefficiencies in in-store logistics due to the lack of inventory visibility. In this paper, we present a product availability monitoring system, which anticipates stockouts before they occur and triggers the personnel to replenish the shelf. Our monitoring system is based on inexpensive polyolefin foam, which serves as mount for capacitive sensing elements. Our sensor system is designed for roll-to-roll based manufacturing, which suggests low production costs. Preliminary tests suggest that the system offers sufficient sensitivity to accurately and reliably detect low quantities of stocks. This will not only reduce losses of sales but also increase customer satisfaction.

Radio frequency identification (RFID) may be used to automatically detect, locate and/or identify objects, making it an ideal candidate for many pervasive computing applications. As RFID technology improves in terms of cost and performance, it is increasingly being explored in a variety of applications, ranging from eldercare through to the smart supply chain. However, while passive UHF RFID has many benefits over other RFID variants, reliable operation as the tag moves in the environment is inherently difficult to predict and can represent a significant challenge. In this paper, we present a novel and practical experimental method called attenuation-thresholding which may be used to characterize the operating range of such RFID systems. The results presented demonstrate the advantages of our method over the conventional read-rate approach. We also demonstrate a novel approach to collecting the measurements in range characterization experiments using robotic automation. Finally, we show how the application of attenuation-thresholding in combination with robotic automation can be used to optimize tag placement on an object. In addition to the clear relevance of this work to the many RFID-based pervasive computing applications reported in the literature and currently under development, it also has broad applicability in other RFID application domains. We conclude with a number of ideas for future extensions to this work.

We propose a method through which dynamic sensor nodes determine that they move together by communicating and correlating their movement information. We describe two possible solutions, one using inexpensive tilt switches, and another one using low-cost MEMS accelerometers. We implement a fast, incremental correlation algorithm, which can run on resource constrained devices. The tests with the implementation on real sensor nodes show that the method distinguishes between joint and separate movements. In addition, we analyse the scalability from four different perspectives: communication, energy, memory and execution speed. The solution using tilt switches proves to be simpler, cheaper and more energy efficient, while the accelerometer-based solution is more accurate and more robust to sensor alignment problems.

In typical location fingerprinting systems a tracked terminal reports sampled values to a location server, which estimates its position based on a database of pre-recorded RSS fingerprints. So far, poll-based and periodic RSS reporting has been proposed. However, for supporting proactive , triggered by pre-defined spatial events, the periodic protocol is inefficient. Hence, this paper introduces zone-based RSS reporting: the location server translates geographical zones defined by the LBS into RSS-based representations, which are dynamically configured with the terminal. The terminal, in turn, reports its measurements only when they match with the configured RSS patterns. As a result, the number of messages exchanged between terminal and server is strongly reduced, saving battery power, bandwidth and also monetary costs spent for mobile bearer services. The paper explores several methods for realizing zone-based RSS reporting and evaluates them simulatively and analytically. An adaption of classical Bayes estimation turns out to be the best suited method.

While commercial solutions for precise indoor positioning exist, they are costly and require installation of additional infrastructure, which limits opportunities for widespread adoption. Inspired by robotics techniques of Simultaneous Localization and Mapping (SLAM) and computer vision approaches using structured light patterns, we propose a self-contained solution to precise indoor positioning that requires no additional environmental infrastructure. Evaluation of our prototype, called TrackSense, indicates that such a system can deliver up to 4 cm accuracy with 3 cm precision in rooms up to five meters squared, as well as 2 degree accuracy and 1 degree precision on orientation. We explain the design and performance characteristics of our prototype and demonstrate a feasible miniaturization that supports applications that require a single device localizing itself in a space. We also discuss extensions to locate multiple devices and limitations of this approach.