Mohamed Bishr

Geospatial Information Bottom-Up: A Matter of Trust and Semantics

Geographic Information Science and business are facing a new challenge: understanding and exploiting data and services emerging from online communities. In the emerging technologies of the social web, GI user roles switched from being data consumers to become data producers, the challenge we argue is in making this generated GI usable. As a use case we point to the increasing demands for up-to-date geographic information combined with the high cost of maintenance which present serious challenges to data providers. In this paper we argue that the social web combined with social network science present a unique opportunity to achieve the goal of reducing the cost of maintenance and update of geospatial data and providing a platform for bottom up approaches to GI. We propose to focus on web-based trust as a proxy measure for quality and to study its spatio-temporal dimensions. We also point to work on combining folksonomies with ontologies, allowing for alternative models of metadata and semantics as components of our proposed vision.

An agenda for the next generation gazetteer: geographic information contribution and retrieval

Gazetteers are key components of georeferenced information systems, including applications such as Web-based mapping services. Existing gazetteers lack the capabilities to fully integrate user-contributed and vernacular geographic information, as well as to support complex queries. To address these issues, a next generation gazetteer should leverage formal semantics, harvesting of implicit geographic information -- such as geotagged photos -- as well as models of trust for contributors. In this paper, we discuss these requirements in detail. We elucidate how existing standards can be integrated to realize a gazetteer infrastructure allowing for bottom-up contribution as well as information exchange between different gazetteers. We show how to ensure the quality of user-contributed information and demonstrate how to improve querying and navigation using semantics-based information retrieval.

To ontologise or not to ontologise: An information model for a geospatial knowledge infrastructure

A geospatial knowledge infrastructure consists of a set of interoperable components, including software, information, hardware, procedures and standards, that work together to support advanced discovery and creation of geoscientific resources, including publications, data sets and web services. The focus of the work presented is the development of such an infrastructure for resource discovery. Advanced resource discovery is intended to support scientists in finding resources that meet their needs, and focuses on representing the semantic details of the scientific resources, including the detailed aspects of the science that led to the resource being created. This paper describes an information model for a geospatial knowledge infrastructure that uses ontologies to represent these semantic details, including knowledge about domain concepts, the scientific elements of the resource (analysis methods, theories and scientific processes) and web services. This semantic information can be used to enable more intelligent search over scientific resources, and to support new ways to infer and visualise scientific knowledge. The work describes the requirements for semantic support of a knowledge infrastructure, and analyses the different options for information storage based on the twin goals of semantic richness and syntactic interoperability to allow communication between different infrastructures. Such interoperability is achieved by the use of open standards, and the architecture of the knowledge infrastructure adopts such standards, particularly from the geospatial community. The paper then describes an information model that uses a range of different types of ontologies, explaining those ontologies and their content. The information model was successfully implemented in a working geospatial knowledge infrastructure, but the evaluation identified some issues in creating the ontologies.

Trustworthiness Attributes and Metrics for Engineering Trusted Internet-Based Software Systems

Trustworthiness of Internet-based software systems, apps, services and platform is a key success factor for their use and acceptance by organizations and end-users. The notion of trustworthiness, though, is subject to individual interpretation and preference, e.g., organizations require confidence about how their business critical data is handled whereas end-users may be more concerned about usability. As one main contribution, we present an extensive list of software quality attributes that contribute to trustworthiness. Those software quality attributes have been identified by a systematic review of the research literature and by analyzing two real-world use cases. As a second contribution, we sketch an approach for systematically deriving metrics to measure the trustworthiness of software system. Our work thereby contributes to better understanding which software quality attributes should be considered and assured when engineering trustworthy Internet-based software systems.

Trust and Reputation Models for Quality Assessment of Human Sensor Observations

With the rise of human sensor observation as a major source of geospatial information, the traditional assessment of information quality based on parameters like accuracy, consistency and completeness is shifting to new measures. In volunteered geographic information (VGI) these conventional parameters are either lacking or not explicit. Regarding human observation quality as fitness for purpose, we propose to use trust and reputation as proxy measures of it. Trustworthy observations then take precedence over less trustworthy observations. Further, we propose that trust and reputation have spatial and temporal dimensions and we build computational models of trust for quality assessment including these dimensions. We present the case study of the H2.0 VGI project for water quality management. Through agent based modeling, the study has established the validity of a spatio-temporal trust model for assessing the trustworthiness and hence the quality of human observations. We first introduce a temporally sensitive trust model and then discuss the extension of the temporal model with spatial dimensions and their effects on the computational trust model.

eScience for Sea Science: A Semantic Scientific Knowledge Infrastructure for Marine Scientists

The COastal and Marine Perception Application for Scientific Scholarship (COMPASS) is a knowledge infrastructure that supports enhanced discovery of scientific resources, including publications, data sets and web services. It provides users with the ability to discover resources on the basis of domain knowledge using ontologies, and scientific knowledge, including the scientific models, theories and methods that were used to conduct the research described by the resource. The application includes an architecture that adopts standards from the geospatial information community to ensure interoperability between repositories and allow interaction with content from digital libraries. The architecture shows how ontologies can be used as a registry for an interoperable infrastructure. A prototype was successfully implemented and evaluated with users, finding enthusiasm and support for the approach, with some suggestions for improvements of the prototype implementation.

Finding Science with Science: Evaluating a Domain and Scientific Ontology User Interface for the Discovery of Scientific Resources

Current approaches to the discovery of scientific resources (publications, data sets and web services) are dominated by keyword search. These approaches do not allow scientists to search on the deeper semantics of scientific resources, or to discover resources on the basis of the scientific approaches taken. This article evaluates a user interface that allows users to discover scientific resources through structured knowledge in the form of ontologies describing the domain and the scientific knowledge inherent within the scientific resource, and also through informal user tags. These combined capabilities provide scientists with new and powerful options for resource discovery. A qualitative user evaluation explored how scientists felt about the approach for resource discovery in the context of their scientific work. The study showed that marine scientists were enthusiastic about the capabilities of such an approach and appreciated the ability to browse the visual structure of the knowledge and query on scientific method but, overall, preferred the use of tags over ontologies. The exploratory nature of the user study was used to identify future directions for such improvements.

Trust and trustworthiness maintenance: From architecture to evaluation

Embedded systems, by their nature, often run unattended with opportunistic rather then scheduled software upgrades and, perhaps most significantly, have long operational lifetimes, and, hence, provide excellent targets for massive and remote exploitation. Thus, such systems mandate higher assurances of trust and cyber-security compared to those presently available in State-of-the-Art ICT systems. In this poster we present some techniques we utilize in the SHARCS project to ensure a higher level of security for embedded systems.In recent years, low-end embedded devices have been used increasingly in various scenarios, ranging from consumer electronics to industrial equipment. However, this evolution made embedded devices profitable targets for software piracy and software manipulation. Aggravating this situation, low-end embedded devices typically lack secure hardware to effectively protect against such attacks. In this work, we present a novel software protection scheme, which is particularly suited for already deployed low-end embedded devices without secure hardware. Our approach combines techniques based on self-checksumming code with Physically Unclonable Functions (PUFs) to establish a hardwareassisted software protection. In this way, we can tie the execution of a software instance to a specific device and protect its program code against manipulations. We show that our software protection scheme offers a high level of security against static adversaries and demonstrate that dynamic adversaries require considerable resources to perform a successful attack. To explore the feasibility of our solution, we implemented the protection scheme on an ARM-based low-end commodity microcontroller. A further performance evaluation shows that the implemented solution exhibits a fair overhead of ten percent.