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Access control systems for geo-spatial data and applications
Full text linkData security is today an important requirement in various applications because of the stringent need to ensure confidentiality, integrity, and availability of information. Comprehensive solutions to data security are quite complicated and require the integration of different tools and techniques as well as specific organizational processes. In such a context, a fundamental role is played by the access control system (ACS) that establishes which subjects are authorized to perform which operations on which objects. Subjects are individuals or programs or other entities requiring access to the protected resources. When dealing with protection of information, the resources of interest are typically objects that record information, such as files in an operating system, tuples in a relational database, or a complex object in an object database. Because of its relevance in the context of solutions for information security, access control has been extensively investigated for database management systems (DBMSs) [6], digital libraries [3, 14], and multimedia applications [24]. Yet, the importance of the spatial dimension in access control has been highlighted only recently. We say that access control has a spatial dimension when the authorization to access a resource depends on position information.We broadly categorize spatially aware access control as object-driven, subject-driven, and hybrid based on whether the position information concerns objects, subjects, or both, respectively. In the former case, the spatial dimension is introduced because of the spatial nature of resources. For example, if the resources are georeferenced Earth images, then we can envisage an individual be allowed to only display images covering a certain region. The spatial dimension may also be required because of the spatial nature of subjects. This is the case of mobile individuals allowed to access a resource when located in a given area. For example, an individual may be authorized to view secret information only within a military base. Finally, position information may concern both objects and subjects like in the case of an individual authorized to display images of a region only within a military office. There is a wide range of applications which motivate spatially aware access control. The two challenging and contrasting applications we propose as examples 190 Maria Luisa Damiani and Elisa Bertino are the spatial data infrastructures (SDI) and location-based services (LBS). An SDI consists of the technological and organizational infrastructure which enables the sharing and coordinated maintenance of spatial data among multiple heterogeneous organizations, primarily public administrations, and government agencies. On the other side, LBS enable mobile users equipped with location-aware terminals to access information based on the position of terminals. These applications have different requirements on access control. In an SDI, typically, there is the need to account for various complex structured spatial data that may have multiple representations across different organizations. In an SDI, the access control is thus object-driven. Conversely, in LBS, there is the need to account for a dynamic and mobile user population which may request diversified services based on position. Access control is thus subject-driven or hybrid. However, despite the variety of requirements and the importance of spatial data protection in these and other applications, very few efforts have been devoted to the investigation of spatially aware access control models and systems. In this chapter, we pursue two main goals: the first is to present an overview of this emerging research area and in particular of requirements and research directions; the second is to analyze in more detail some research issues, focusing in particular on access control in LBS. We can expect LBS to be widely deployed in the near future when advanced wireless networks, such as mobile geosensor networks, and new positioning technologies, such as the Galileo satellite system will come into operation. In this perspective, access control will become increasingly important, especially for enabling selective access to services such as Enterprise LBS, which provide information services to mobile organizations, such as health care and fleet management enterprises. An access control model targeting mobile organizations is GEO-RBAC [4]. Such a model is based on the RBAC (role-based access control) standard and is compliant with Open Geospatial Consortium (OGC) standards with respect to the representation of the spatial dimension of the model. The main contributions of the chapter can be summarized as follows: • We provide an overview of the ongoing research in the field of spatially aware access control. • We show how the spatial dimension is interconnected with the security aspects in a specific access control model, that is, GEO-RBAC. • We outline relevant architectural issues related to the implementation of an ACS based on the GEO-RBAC model. In particular, we present possible strategies for security enforcement and the architecture of a decentralized ACS for large-scale LBS applications. The chapter is organized as follows. The next section provides some background knowledge on data security and in particular access control models. The subsequent section presents requirements for geospatial data security and then the state of the art. Afterward the GEO-RBAC model is introduced. In particular, we present the main concepts of the model defined in the basic layer of the model, the Core GEO-RBAC. Hence, architectural approaches supporting GEO-RBAC are presented. Open issues are finally reported in the concluding section along with directions for future work
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
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