An orientation free adaptive step detection algorithm using a smart phone in physical activity monitoring

In this paper we present an Orientation Free Adaptive Step Detection (OFASD) algorithm for deployment in a smart phone for the purposes of physical activity monitoring. The OFASD algorithm detects individual steps and measures a user’s step counts using the smart phone’s in-built accelerometer. The algorithm considers both the variance of an individual’s walking pattern and the orientation of the smart phone. Experimental validation of the algorithm involved the collection of data from 10 participants using five phones (worn at five different body positions) whilst walking on a treadmill at a controlled speed for periods of 5 min. Results indicated that, for steps detected by the OFASD algorithm, there were no significant differences between where the phones were placed on the body (p > 0.05). The mean step detection accuracies ranged from 93.4 % to 96.4 %. Compared to measurements acquired using existing dedicated commercial devices, the results demonstrated that using a smart phone for monitoring physical activity is promising, as it adds value to an accepted everyday accessory, whilst imposing minimum interaction from the user. The algorithm can be used as the underlying component within an application deployed within a smart phone designed to promote self-management of chronic disease where activity measurement is a significant factor, as it provides a practical solution, with minimal requirements for user intervention and less constraints than current solutions.

Interobserver Reliability of Radiologists' Interpretations of Mobile Chest Radiographs for Nursing Home-Acquired Pneumonia

Objectives: To determine the interobserver reliability of radiologists' interpretations of mobile chest radiographs for nursing home-acquired pneumonia. Design: A cross-sectional reliability study. Setting: Nursing homes and an acute care hospital. Participants: Four radiologists reviewed 40 mobile chest radiographs obtained from residents of nursing homes who met a clinical definition of lower respiratory tract infections. Measurements: Radiologists were asked to interpret radiographs with respect to the film quality; presence, pattern, and extent of an infiltrate; and the presence of a pleural effusion or adenopathy. Interrater reliability was evaluated using the intraclass correlation coefficient derived from a 2-way random effects model. Results: On average the radiologists reported that 6 of the 40 films were of very good or excellent quality and 16 of the 40 were of fair or poor quality. When the finding of an infiltrate was dichotomized (0 = no; 1 = possible, probable, or definite) all 4 radiologists agreed on 21 of the 37 chest radiographs. The intraclass correlation coefficient for the presence or absence of infiltrates was 0.54 (95% confidence intervals [CI] 0.38 to 0.69). For the 14 radiographs where infiltrates were observed by all radiologists, intraclass correlation coefficients for the presence of pleural effusions was 0.08 (95% CI -0.10 to 0.41), hilar adenopathy 0.54 (95% CI 0.29 to 0.79), and mediastinal adenopathy 0.49 (95% CI 0.21 to 0.76). Conclusion: In conclusion, the interrater agreement among radiologists for mobile chest radiographs in establishing the presence or absence of an infiltrate can be judged to be "fair." Treatment decisions need to include clinical findings and should not be made based on radiographic findings alone. © 2006 American Medical Directors Association.

A qualitative enquiry into the appropriation of mobile telephony at the bottom of the pyramid

Purpose: The paper aims to analyse Bottom of the Pyramid (BoP) customers’ (e.g. Bangladeshi farmers) use and appropriation of mobile telephony and to critically identify a suitable research strategy for such investigation.

Design/methodology/approach: Concentrated ethnographic immersion was combined with both methodological and investigator triangulation during a four-month period of fieldwork conducted in Bangladeshi villages to obtain more robust findings. Concentrated immersion was required to achieve relatively speedier engagement owing to the difficulty in engaging with respondents on a long-term basis.

Findings: The farmers’ use of mobile telephony went beyond the initial adoption, as they appropriated it through social and institutional support, inventive means and/or changes in their own lifestyle. The paper argues that technology appropriation, being a result of the mutual shaping of technology, human skills and abilities and macro-environmental factors, enables users to achieve desired outcomes which may not always be the ones envisaged by the original designers.

Research limitations/implications: The paper contributes to two major areas: first, it identifies technology appropriation as an important and emerging concept in international marketing research; second, it suggests a concentrated form of ethnographic engagement for studying technology appropriation in a developing country context.

Practical implications: A good understanding of the dynamic interplay between users’ skills and abilities, social contexts and technological artefacts/applications is required in order for businesses to serve BoP customers profitably.

Originality/value: The paper presents a dynamic model of technology appropriation based on findings collected through a pragmatic approach by combining concentrated ethnographic immersion with methodological and investigator triangulation

Making geography mobile: using location aware technology to improve student performance in physical geography

With the increased availability of new technologies, geography educators are revisiting their pedagogical approaches to teaching and calling for opportunities to share local and international practices which will enhance the learning experience and improve students’ performance. This paper reports on the use of handheld mobile devices, fitted with GPS, by secondary (high) school pupils in geography. Two location-aware activities were completed over one academic year (one per semester) and pre-test and post-test scores for both topics revealed a statistically significant increase in pupils’ performance as measured by the standard national assessments. A learner centred educational approach was adopted with the first mobile learning activity being created by the teacher as an exemplar of effective mobile learning design. Pupils built on their experiences of using mobile learning when they were required to created their own location aware learning task for peer use. An analysis of the qualitative data from the pupils’ journals, group diaries and focus group interviews revealed the five pillars of learner centred education are addressed when using location aware technologies and the use of handheld mobile devices offered greater flexibility and autonomy to the pupils thus altering the level of power and control away from the teacher. Due to the relatively small number of participants in the study, the results are more informative than generalisable however in light of the growing interest in geo-spatial technologies in geography education, this paper offers encouragement and insight into the use of location aware technology in a compulsory school context

Retrodirective Terminal Antenna for Satellite and Terrestrial Mobile Communications

The potential for implementation of retrodirective arrays as antenna terminals for future integrated satellite and terrestrial mobile communications is discussed in this paper. Particularly, in the context of the Inmarsat L-band system we address the issues related to array antenna element capacity to produce high-quality circular polarized radiation pattern over large angles of arrival. We also discuss circuitry reduction methodologies and their effect on retrodirected beam characteristics. The possibility of circular polarization modulation of the re-transmit signal is also discussed.

An exploration of seniors’ motivation to use mobile brain-exercise software

This article reports on the development of an iPhone-based brain-exercise tool for seniors involving a series of focus groups (FGs) and field trials (FTs). Four FGs with 34 participants were conducted aimed at understanding the underlying motivational and de-motivational factors influencing seniors’ engagement with mobile brain-exercise software. As part of the FGs, participants had approximately 40 minutes hands-on experience with commercially available brain-exercise software. A content analysis was conducted on the data resulting in a ranking of 19 motivational factors, of which the top three were challenge, usefulness and familiarity and 15 de-motivational factors, of which the top-three were usability issues, poor communication and games that were too fast. Findings were used to inform the design of three prototype brain-exercise games for the iPhone contained within one overall application, named Brain jog. Subsequently, two FTs were conducted using Brain jog to investigate the part that time exposure has to play in shaping the factors influencing engagement. New factors arose with respect to the initial FGs including the motivational factor feedback and the de-motivational factor boring. The results of this research provide valuable guidelines for the design and evaluation of mobile brain-exercise software for seniors.

Investigation of the M2/G2/1/ ∞, N Queue with Restricted Admission of Priority Customers and its Application to HSDPA Mobile Systems

This paper investigates a queuing system for QoS optimization of multimedia traffic consisting of aggregated streams with diverse QoS requirements transmitted to a mobile terminal over a common downlink shared channel. The queuing system, proposed for buffer management of aggregated single-user traffic in the base station of High-Speed Downlink Packet Access (HSDPA), allows for optimum loss/delay/jitter performance for end-user multimedia traffic with delay-tolerant non-real-time streams and partially loss tolerant real-time streams. In the queuing system, the real-time stream has non-preemptive priority in service but the number of the packets in the system is restricted by a constant. The non-real-time stream has no service priority but is allowed unlimited access to the system. Both types of packets arrive in the stationary Poisson flow. Service times follow general distribution depending on the packet type. Stability condition for the model is derived. Queue length distribution for both types of customers is calculated at arbitrary epochs and service completion epochs. Loss probability for priority packets is computed. Waiting time distribution in terms of Laplace-Stieltjes transform is obtained for both types of packets. Mean waiting time and jitter are computed. Numerical examples presented demonstrate the effectiveness of the queuing system for QoS optimization of buffered end-user multimedia traffic with aggregated real-time and non-real-time streams.

CoWiSMoN: A Framework for Cognitive Wireless Sensor Mobile Network System for Emergency Rescue Management

One of the crucial aspects of disaster management of emergency situations is the early assessment of needs and damages. In most disaster situations, higher fatality and increased casualty results from lack of access to timely available emergency services rather than the initial disaster itself. This is usually caused by lack of access to the affected area in order to properly assess the situation for relevant and urgent measures. Cognitive wireless sensor networks provide an opportunity to overcome this situation especially through interconnection via mobile systems. This paper presents a cognitive wireless sensor mobile networks-based framework (CoWiSMoN), designed to offer real-time emergency services to victims and rescue personnel in event of disasters. Critical issues underlying the implementation of such a system are discussed and analyzed.