To provide mobility assistance for people with disabilities, pedestrian network data that includes accessibility attributes within public spaces is required. The freshness of data is necessary as public space conditions change frequently; however, its regular maintenance incurs substantial costs. In this paper, we propose a data platform for an accessible pedestrian network with a workflow similar to continuous software development. With this approach, the platform aims to allow local governments and citizens to maintain data in a collaborative and sustainable manner. This paper reports the initial phase of our project aiming at realizing such a platform; we designed and prototyped a platform based on this idea and conducted an actual field experiment in a specific area of Tokyo. Through this experiment, we demonstrated the feasibility of this idea and gained valuable insights for practical implementation.

Under the COVID-19 pandemic, it is necessary to balance social distancing and continuous economic activities. In this study, we report on our developed service that forecasts the congestion level of regional commercial facilities using point-of-sales (POS) statistics. POS statistics data were collected for over a year from 150 commercial facilities in Tokyo. Through the analysis of a total of over 100 million customers, we clarified the factors that affect congestion levels of commercial facilities in each ward of Tokyo. Based on this analysis, we developed a congestion forecast model that predicts future congestion levels from several factors such as a big event, business restrictions, and weather. We implemented a web service incorporating this model and published estimated congestion levels both on our website and a television program. The experimental results show that the model has a high prediction accuracy with a coefficient of determination greater than 0.95 on average, which implies that big data from POS has great potential for value creation under the pandemic.

Context-awareness is a quintessential feature of ubiquitous computing. Contextual information not only facilitates improved applications, but can also become significant security parameters -- which in turn can potentially ensure service delivery not to anyone anytime anywhere, but to the right person at the right time and place. Specially, in determining access control to resources, contextual information can play an important role. Access control models, as studied in traditional computing security, however, have no notion of context-awareness; and the recent works in the nascent field of context-aware access control predominantly focus on spatio-temporal contexts, disregarding a host of other pertinent contexts. In this paper, with a view to exploring the relationship of access control and context-awareness in ubiquitous computing, we propose a comprehensive context-aware access control model for ubiquitous healthcare services. We explain the design, implementation and evaluation of the proposed model in detail. We chose healthcare a representative application domain because healthcare systems pose an array of non-trivial context-sensitive access control requirements, many of which are directly or indirectly applicable to other context-aware ubiquitous computing applications.

Internet commerce is increasing the demands of service integrations by sharing XML-based catalogs. We propose the PCO (Portable Compound Object) data model supporting semantic inheritance to ensure the synonymy of heterogeneous semantics among distributed schemas that different authors define independently. Also, the PCO model makes semantic relationships independent of an initial class hierarchy, and it enables rapid schema evolution across the entire Internet business. This preserves semantic interoperability without changing pre-defined classes. We have also encoded the PCO model into two XML-based languages: the PCO Specification Language (PSL) and the Portable Composite Language (PCL). This paper demonstrates that intermediaries defining service semantics in PSL can automatically integrate multiple suppliers' PCL catalogs for their agent-mediated services.