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Background Insufficient physical activity (PA) is a risk factor for obesity and non-communicable diseases and seems more prevalent among socioeconomically disadvantaged (SED) adults. Recreational walking (RW) is an important type of leisure time PA which can be done for free and without specific equipment or facilities. Environmental factors influencing PA may be particularly important for SED adults who are more reliant on their direct environment. The objectively measured environment is not always congruent with the perception of residents, and this may differ by socioeconomic group. This study aims to identify the local environmental factors important for RW as perceived by SED adults. Methods This study is part of the CIVISANO project. Purposeful convenience sampling was used to recruit 38 SED adults (25-65 y/o) in two Flemish semi-urban municipalities. Individual walk-along interviews have been performed in the participants’ neighborhood. 20 participants joined the focus group discussion (n = 4) that were intended for member checking, to categorize identified environmental factors and to identify local actions to promote recreational walking. MaxQDA was used for content analysis. Results The way the environment is perceived by SED adults plays an important role in their RW behavior. Results demonstrate the interrelation of different environmental types (physical, sociocultural, economic, political and information) and sizes (micro, meso, macro). Improving communication and knowledge transfer, stimulation of physical, sociocultural, and economic accessibility, and promotion of physical and social safety are identified most important action points for the local government to facilitate RW. Conclusions Our findings indicate that the perceived local environment can play an important role in promoting RW among SED adults. Future studies should investigate if changes in these environments and in residents’ perception lead to changes in RW behavior of SED adults. Key messages

Ad hoc shared ride trip planning (SRTP) utilizes mobile devices, geo-sensors and wireless networks to match on-the-fly individual travel demand with transport supply. It represents one of many alternatives to single occupancy vehicle use. This paper outlines a SRTP approach via a two-phase algorithm based on user preferences in a time-dependent routing. Whereas current algorithms use minimization of travel time as the only optimization criterion in trip planning, in the framework presented here, the user can specify multiple trip preferences including travel time, walking time, number of transfers between cars and trip length. Various scenarios are simulated in the city of Tehran (Iran) to demonstrate how preference settings affect the routes of ad hoc shared journeys.

When studying geographical phenomena, different levels of spatial and temporal granularity often have to be considered. While various approaches have been proposed to analyse geographical data in a multi-scale perspective, they have all focused on either spatial or temporal attributes rather than on the integration of space and time over multiple scales. This study introduces the continuous spatio-temporal model (CSTM), a conceptual model that seeks to address this shortcoming. The presented model is based on (1) the continuous temporal model (CTM), a multi-scale model for temporal information, and (2) the continuous spatial model (CSM), an extension of CTM for multi-scale spatial raster data. At the core of the presented conceptual model is a spatio-temporal evolution element or, in short, stevel, which is described by four variables: (1) pixel location, (2) spatial resolution, (3) temporal interval, and (4) temporal resolution. By varying one or more of these variables, a CSTM-tree consisting of (sets o...

As positional error is a major issue in the assessment of spatial data quality, its propagation has been studied widely in map overlaying. However, few studies deal with a manifest consequence of positional error in map overlaying, namely sliver polygons. Sliver polygons are generally treated as awkward by-products that need to be removed quickly. Nevertheless, as they represent spurious areas, their nature and properties carry useful information, for example, for land use/cover assessment. Therefore, next to sliver removal, there is a need for intelligent detection and eventually further analysis of sliver polygons. This article proposes a general, semi-automated method for the assessment of slivers in vector polygon layers. A case study in Flanders (Belgium) illustrates a possible application in area estimation evaluation of land use allocation classes.

Constraint-based models and models constructing accessibility measures mainly focus on single agents having only one available transport mode. However, numerous cases exist where multiple agents or groups of individuals with different available transport modes want to participate in a joint activity at a certain location. The aim of this paper is to provide new insights into representing and reasoning about feasible space-time opportunities for multiple agents. Relying on concepts of time geography, we propose a conceptual framework in order to determine interaction spaces for groups of individuals. Besides availability of means of transport and the locations of each individual, minimum activity duration and opening hours of opportunities are taken into account. The reasoning about space and time is visualized in three dimensions using a hybrid (CAD/GIS) system.

In recent years, the interest of many researchers in various domains is triggered to move beyond the traditional border of twodimensionality and explore the possibilities of the third and even the fourth, temporal, dimension. The emerging research interest concerning 3D and 4D and the handling of these additional dimensions can bring many benefits to archaeology as well. A 4D GIS tailored to archaeological data would facilitate better insights and more complex analyses. Its basis must be a conceptual 4D archaeological data model, which pays attention to existing data models and standards. Although in some cases more complex, archaeological data are closely related to geography and geo-information. Since the temporal dimension is a, and possibly the most, substantial element in archaeological research, this paper focusses mainly on this dimension. In this paper, the applicability of the ISO 19108 geo-information standard on temporal information for archaeological data is investigated. For a set of common temporal categories, e.g. the excavation time, the appropriate description according to this standard is determined. This will indicate in which cases the internationally recognized standard is suitable for use in an archaeological data model. Furthermore, three versions of the West European archaeological time scale as temporal ordinal reference system are constructed. For the first version, the ISO 19108 structure is used, whereas the second and third are based on geological variants. The results of the performed analysis are favourable to the usability of the ISO 19108 standard in archaeology; however, other temporal standards or data models may yield up better results.

This paper outlines the potential use of Bluetooth tracking of mobile devices in an urban environment for an intelligent and adaptive management of large-scale events. The used methodology is explained in detail, and its information potential is demonstrated through results that were gathered and processed offline. Additionally, a near-future project where the methodology will also generate real-time information is outlined, together with the system architecture necessary for this aim.

This paper introduces a qualitative approach to the analysis and comparison of the shape of polygons