Long-term experiments with an adaptive spherical view representation for navigation in changing environments

Real-world environments such as houses and offices change over time, meaning that a mobile robot’s map will become out of date. In this work, we introduce a method to update the reference views in a hybrid metrictopological map so that a mobile robot can continue to localize itself in a changing environment. The updating mechanism, based on the multi-store model of human memory, incorporates a spherical metric representation of the observed visual features for each node in the map, which enables the robot to estimate its heading and navigate using multi-view geometry, as well as representing the local 3D geometry of the environment. A series of experiments demonstrate the persistence performance of the proposed system in real changing environments, including analysis of the long-term stability.

Nano and ultrafine particle number concentrations in different environments : application towards air quality regulations

Particle number concentrations vary significantly with environment and, in this study, we attempt to assess the significance of these differences. Towards this aim, we reviewed 85 papers that have reported particle number concentrations levels at 126 sites covering different environments. We grouped the results into eight categories according to measurement location including: road tunnel, on-road, road-side, street canyon, urban, urban background, rural, and clean background. From these reports, the overall median number concentration for each of the eight site categories was calculated. The eight location categories may be classified into four distinct groups. The mean median particle number locations for these four types were found to be statistically different from each other. Rural and clean background sites had the lowest concentrations of about 3x103 cm-3. Urban and urban background sites showed concentrations that were three times higher (9x103 cm-3). The mean concentration for the street canyon, roadside and on-road measurement sites was 4.6x104 cm-3, while the highest concentrations were observed in the road tunnels (8.6x104 cm-3). This variation is important when assessing human exposure-response for which there is very little data available, making it difficult to develop health guidelines, a basis for national regulations. Our analyses shows that the current levels in environments affected by vehicle emissions are 3 to 28 times higher than in the natural environments. At present, there is no threshold level in response to exposure to ultrafine particles. Therefore, future control and management strategies should target a decrease of these particles in urban environments by more than one order of magnitude to bring them down to the natural background. At present there is a long way to go to achieve this.

Comparison of particle number concentrations between different environments

Particle number concentrations vary significantly with environment and, in this study, we attempt to assess the significance of these differences. Towards this aim, we reviewed 85 papers that have reported particle number concentrations levels at 126 sites covering different environments. We grouped the results into eight categories according to measurement location including: road tunnel, on-road, road-side, street canyon, urban, urban background, rural, and clean background. Median values were calculated for each category. This review was restricted to papers that presented concentrations numerically. The majority of the reports were based on either CPC or SMPS measurements, with a limited number of papers reporting results from both instruments at the same site. Hence there were several overlaps between the number of CPC and SMPS measuring sites. Most of the studies reported multiple measurements at a given study site, while some studies included results from more than one site. From these reports, the overall median value for each location category was calculated...

Student interactivity and teacher participation: An application of legitimate peripheral participation in higher education online learning environments

Lave and Wenger’s legitimate peripheral participation is an important aspect of online learning environments. It is common for teachers to scaffold varying levels of online participation in Web 2.0 contexts, such as online discussion forums and blogs. This study argues that legitimate peripheral participation needs to be redefined in response to students’ decentralised multiple interactions and non-linear engagement in hyperlinked learning environments. The study examines students’ levels of participation in online learning through theories of interactivity, distinguishing between five levels of student participation in the context of a first-year university course delivered via a learning management system. The data collection was implemented through two instruments: i) a questionnaire about students’ interactivity perception in the online reflective learning (n = 238) and then ii) an open discussion on the reason for the diverse perceptions of interactivity (n = 34). The study findings indicate that student participants, other than those who were active, need high levels of teacher or moderator intervention, which better enables legitimate peripheral participation to occur in online learning contexts.

Secondary user relations in emerging mobile computing environments

Mobile technologies are enabling access to information in diverse environ.ments, and are exposing a wider group of individuals to said technology. Therefore, this paper proposes that a wider view of user relations than is usually considered in information systems research is required. Specifically, we examine the potential effects of emerging mobile technologies on end-­‐user relations with a focus on the ‘secondary user’, those who are not intended to interact directly with the technology but are intended consumers of the technology’s output. For illustration, we draw on a study of a U.K. regional Fire and Rescue Service and deconstruct mobile technology use at Fire Service incidents. Our findings provide insights, which suggest that, because of the nature of mobile technologies and their context of use, secondary user relations in such emerging mobile environments are important and need further exploration.

Vision-based simultaneous localization and mapping in changing outdoor environments

For robots operating in outdoor environments, a number of factors, including weather, time of day, rough terrain, high speeds, and hardware limitations, make performing vision-based simultaneous localization and mapping with current techniques infeasible due to factors such as image blur and/or underexposure, especially on smaller platforms and low-cost hardware. In this paper, we present novel visual place-recognition and odometry techniques that address the challenges posed by low lighting, perceptual change, and low-cost cameras. Our primary contribution is a novel two-step algorithm that combines fast low-resolution whole image matching with a higher-resolution patch-verification step, as well as image saliency methods that simultaneously improve performance and decrease computing time. The algorithms are demonstrated using consumer cameras mounted on a small vehicle in a mixed urban and vegetated environment and a car traversing highway and suburban streets, at different times of day and night and in various weather conditions. The algorithms achieve reliable mapping over the course of a day, both when incrementally incorporating new visual scenes from different times of day into an existing map, and when using a static map comprising visual scenes captured at only one point in time. Using the two-step place-recognition process, we demonstrate for the first time single-image, error-free place recognition at recall rates above 50% across a day-night dataset without prior training or utilization of image sequences. This place-recognition performance enables topologically correct mapping across day-night cycles.

Wearable neuroimaging and emotion : investigating emotional responses to architectural environments with functional near-infrared spectroscopy (fNIRS)

Supported by contemporary theories of architectural aesthetics and neuro-aesthetics this paper presents a case for the use of portable fNIRS imaging in the assessment of emotional responses to spatial environments experienced by both blind and sighted. The aim of the paper is to outline the implications of fNIRS for spatial research and practice within the field of architecture, thereby suggesting a potential taxonomy of particular formations of space and affect. Empirical neurological study of affect and spatial experience from an architectural design perspective remains in many instances unchartered. Clinical research using the portable non-invasive neuro-imaging device, functional near infrared spectroscopy (fNIRS) is proving convincing in its ability to detect emotional responses to visual, spatio-auditory and task based stimuli, providing a firm basis to potentially track cortical activity in the appraisal of architectural environments. Additionally, recent neurological studies have sought to explore the manifold sensory abilities of the visually impaired to better understand spatial perception in general. Key studies reveal that early blind participants perform as well as sighted due to higher auditory and somato-sensory spatial acuity. For instance, face vision enables the visually impaired to detect environments through skin pressure, enabling at times an instantaneous impression of the layout of an unfamiliar environment. Studies also report pleasant and unpleasant emotional responses such as ‘weightedness’ or ‘claustrophobia’ within certain interior environments, revealing a deeper perceptual sensitivity then would be expected. We conclude with justification that comparative fNIRS studies between the sighted and blind concerning spatial experience have the potential to provide greater understanding of emotional responses to architectural environments.

Form-based planning and liveable urban environments

This review article discusses form-based planning an din details analise the following books: Stepehn Marshall (2012) Urban Coding and Planning (Routledge, New York, USA, 272pp. pISBN 1135689202). Emily Talen (2012) City Rules: How Regulations Affects Urban Form (Island Press, Washington DC, USA, 254 pp. ISBN 9781597266925). Richard Tomlinson (2012) Australia’s Unintended Cities: the Impact of Housing on Urban Development (CSIRO Publishing, Collingwood, Australia, 194pp. ISBN 9780643103771). The history of the city has been written and rewritten many times: the seminal works of Benevolo (1980) and Mumford (1989) reconstruct how settlements, particularly their urban form, have changed over centuries. Rowe and Koetter (1978), Kostof (1991, 1992), Krier (2003), and Rossi and Eisenmann (1982) address instead the components that shape the urban environment: the architect can aggregate and manipulate squares, streets, parks and public buildings to control urban design. Generally these studies aim to reveal the secret of the traditional city in contraposition to the contemporary townscape characterized by planning and zoning, which are generally regarded as problematic and sterile (Woodward, 2013). The ‘secret rules’ that have shaped our cities have a bearing on the relationship of spaces, mixed uses, public environments and walkability (Walters, 2011)...

Exploring the impact of shared domain knowledge on strategic alignment in the Australian public sector

In this age of ever-increasing information technology (IT) driven environments, governments/or public sector organisations (PSOs) are expected to demonstrate the business value of the investment in IT and take advantage of the opportunities offered by technological advancements. Strategic alignment (SA) emerged as a mechanism to bridge the gap between business and IT missions, objectives, and plans in order to ensure value optimisation from investment in IT and enhance organisational performance. However, achieving and sustaining SA remains a challenge requiring even more agility nowadays to keep up with turbulent organisational environments. The shared domain knowledge (SDK) between the IT department and other diverse organisational groups is considered as one of the factors influencing the successful implementation of SA. However, SDK in PSOs has received relatively little empirical attention. This paper presents findings from a study which investigated the influence of SDK on SA within organisations in the Australian public sector. The developed research model examined the relationship of SDK between business and IT domains with SA using a survey of 56 public sector professionals and executives. A key research contribution is the empirical demonstration that increasing levels of SDK between IT and business groups leads to increased SA.

Emotion and architectural environments : a case for Functional Near Infrared Spectroscopy (fNIRS) in assessing emotional responses to spatial environments

Collaboration between neuroscience and architecture is emerging as a key field of research as demonstrated in recent times by development of the Academy of Neuroscience for Architecture (ANFA) and other societies. Neurological enquiry of affect and spatial experience from a design perspective remains in many instances unchartered. Research using portable near infrared spectroscopy (fNIRs) - an emerging non-invasive neuro-imaging device, is proving convincing in its ability to detect emotional responses to visual, spatio-auditory and task based stimuli. This innovation provides a firm basis to potentially track cortical activity in the appraisal of architectural environments. Additionally, recent neurological studies have sought to explore the manifold sensory abilities of the visually impaired to better understand spatial perception in general. Key studies reveal that early blind participants perform as well as sighted due to higher auditory and somato-sensory spatial acuity. Studies also report pleasant and unpleasant emotional responses within certain interior environments revealing a deeper perceptual sensitivity than would be expected. Comparative fNIRS studies between the sighted and blind concerning spatial experience has the potential to provide greater understanding of emotional responses to architectural environments. Supported by contemporary theories of architectural aesthetics, this paper presents a case for the use of portable fNIRS imaging in the assessment of emotional responses to spatial environments experienced by both blind and sighted. The aim of the paper is to outline the implications of fNIRS upon spatial research and practice within the field of architecture and points to a potential taxonomy of particular formations of space and affect.

Empirical vehicle-to-vehicle pathloss modeling in highway, suburban and urban environments at 5.8GHz

In this paper, we present a pathloss characterization for vehicle-to-vehicle (V2V) communications based on empirical data collected from extensive measurement campaign performed under line-of-sight (LOS), non-line-of-sight (NLOS) and varying traffic densities. The experiment was conducted in three different V2V propagation environments: highway, suburban and urban at 5.8GHz. We developed pathloss models for each of the three different V2V environments considered. Based on a log-distance power law model, the values for the pathloss exponent and the standard deviation of shadowing were reported. The average pathloss exponent ranges from 1.77 for highway, 1.68 for the urban to 1.53 for the suburban environment. The reported results can contribute to vehicular network (VANET) simulators and can be used by system designers to develop, evaluate and validate new protocols and system designs under realistic propagation conditions.

The effects of geochemical conditions on the establishment and growth of mangrove seedlings in acid sulfate soil environments

Acid sulfate soils (ASS) is a stress factor that is responsible for the failure of some mangrove restoration projects, including abandoned aquaculture ponds converted from mangrove ecosystems. Through experimental and field studies, this research provides a better understanding of the biogeochemistry of ASS disturbance and the response of mangrove seedlings (Rhizophoraceae) under high metal levels and acidic conditions. This study found that mangrove restorations under ASS disturbance can work but with lower numbers of survived seedlings. To prevent toxicity under high levels of metal, seedlings retained metals in their roots and sparingly distributed them into aerial parts with low mobility. The presence of high levels of potential acidity parameters would allow pyrite to oxidise, thus increasing metal levels and acidity, which in turn affected the survival and growth of the seedlings.