A ubiquitous computing environment consists of many resources that need to be identified by users and applications. Users and developers require some way to identify resources by human readable names. In addition, ubiquitous computing environments impose additional requirements such as the ability to work well with ad hoc situations and the provision of names that depend on context. The Non-anchored Unified Naming (NUN) system was designed to satisfy these requirements. It is based on relative naming among resources and provides the ability to name arbitrary types of resources. By having resources themselves take part in naming, resources are able to able contribute their specialized knowledge into the name resolution process, making context-dependent mapping of names to resources possible. The ease of which new resource types can be added makes it simple to incorporate new types of contextual information within names. In this paper, we describe the naming system and evaluate its use.
There have been naming systems not targeted for ubiquitous computing environments that also use relative naming. Tilde @cite_2 and Prospero @cite_0 are file systems based on relative naming. Prospero is also able to support a limited form of location-aware computing by creating symbolic links according to the login terminal of a user @cite_7 .
@cite_0 @cite_7 @cite_2
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As computers become pervasive, users will access processing, storage, and communication resources from locations that have not been practical in the past. Such users will demand support for location-independent computing. While the basic system components used might change as the user moves from place to place, the appearance of the system should remain constant. In this paper we discuss the role of, and requirements for, directory services in support of integrated, location-independent computing. We focus on two specific problems: the server selection problem and the user location problem. We present solutions to these problems based on the Prospero Directory Service. The solutions demonstrate several unique features of Prospero that make it particularly suited for support of location-independent computing. Scholars are increasingly citing electronic “web references” which are not preserved in libraries or full text archives. WebCite is a new standard for citing web references. To “webcite” a document involves archiving the cited Web page through www.webcitation.org and citing the WebCite permalink instead of (or in addition to) the unstable live Web page. This journal has amended its “instructions for authors” accordingly, asking authors to archive cited Web pages before submitting a manuscript. Almost 200 other journals are already using the system. We discuss the rationale for WebCite, its technology, and how scholars, editors, and publishers can benefit from the service. Citing scholars initiate an archiving process of all cited Web references, ideally before they submit a manuscript. Authors of online documents and websites which are expected to be cited by others can ensure that their work is permanently available by creating an archived copy using WebCite and providing the citation information including the WebCite link on their Web document(s). Editors should ask their authors to cache all cited Web addresses (Uniform Resource Locators, or URLs) “prospectively” before submitting their manuscripts to their journal. Editors and publishers should also instruct their copyeditors to cache cited Web material if the author has not done so already. Finally, WebCite can process publisher submitted “citing articles” (submitted for example as eXtensible Markup Language [XML] documents) to automatically archive all cited Web pages shortly before or on publication. Finally, WebCite can act as a focussed crawler, caching retrospectively references of already published articles. Copyright issues are addressed by honouring respective Internet standards (robot exclusion files, no-cache and no-archive tags). Long-term preservation is ensured by agreements with libraries and digital preservation organizations. The resulting WebCite Index may also have applications for research assessment exercises, being able to measure the impact of Web services and published Web documents through access and Web citation metrics. @PARASPLIT [J Med Internet Res 2005;7(5):e60] Privacy is the most often-cited criticism of ubiquitous computing, and may be the greatest barrier to its long-term success. However, developers currently have little support in designing software architectures and in creating interactions that are effective in helping end-users manage their privacy. To address this problem, we present Confab, a toolkit for facilitating the development of privacy-sensitive ubiquitous computing applications. The requirements for Confab were gathered through an analysis of privacy needs for both end-users and application developers. Confab provides basic support for building ubiquitous computing applications, providing a framework as well as several customizable privacy mechanisms. Confab also comes with extensions for managing location privacy. Combined, these features allow application developers and end-users to support a spectrum of trust levels and privacy needs. Recent growth of the Internet has greatly increased the amount of information that is accessible and the number of resources that are available to users. To exploit this growth, it must be possible for users to find the information and resources they need. Existing techniques for organizing systems have evolved from those used on centralized systems, but these techniques are inadequate for organizing information on a global scale. This article describes Prospero, a distributed file system based on the Virtual System Model. Prospero provides tools to help users organize Internet resources. These tools allow users to construct customized views of available resources, while taking advantage of the structure imposed by others. Prospero provides a framework that can tie together various indexing services producing the fabric on which resource discovery techniques can be applied.