595 research outputs found

    Request for Comments: 5616

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    Streaming Internet Messaging Attachments This document describes a method for streaming multimedia attachments received by a resource- and/or network-constrained device from an IMAP server. It allows such clients, which often have limits in storage space and bandwidth, to play video and audio email content. The document describes a profile for making use of the URLAUTHauthorize

    Designing a Planetary-Scale IMAP Service with Conflict-free Replicated Data Types

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    Modern geo-replicated software serving millions of users across the globe faces the consequences of the CAP dilemma, i.e., the inevitable conflicts that arise when multiple nodes accept writes on shared state. The underlying problem is commonly known as fault-tolerant multi-leader replica- tion; actively researched in the distributed systems and database communities. As a more recent theoretical framework, Conflict-free Replicated Data Types (CRDTs) propose a solution to this problem by offering a set of always converging primitives. However, modeling non-trivial system state with CRDT primitives is a challenging and error-prone task. In this work, we propose a solution for a geo-replicated online service with fault-tolerant multi-leader replication based on CRDTs. We chose IMAP as use case due to its prevalence and simplicity. Therefore, we modeled an IMAP-CRDT and verified its correctness with the interactive theorem prover Isabelle/HOL. In order to bridge the gap between theory and practice, we implemented an open-source proto- type pluto and an IMAP benchmark for write-intensive workloads. We evaluated our prototype against the standard IMAP server Dovecot on a multi-continent public cloud. The results ex- pose the limitations of Dovecot with respect to response time performance and replication lag. Our prototype was able to leverage its conceptual advantages and outperformed Dovecot. We find that our approach is promising when facing the multitude of potential concurrency bugs in development of systems at planetary scale

    Curating E-Mails; A life-cycle approach to the management and preservation of e-mail messages

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    E-mail forms the backbone of communications in many modern institutions and organisations and is a valuable type of organisational, cultural, and historical record. Successful management and preservation of valuable e-mail messages and collections is therefore vital if organisational accountability is to be achieved and historical or cultural memory retained for the future. This requires attention by all stakeholders across the entire life-cycle of the e-mail records. This instalment of the Digital Curation Manual reports on the several issues involved in managing and curating e-mail messages for both current and future use. Although there is no 'one-size-fits-all' solution, this instalment outlines a generic framework for e-mail curation and preservation, provides a summary of current approaches, and addresses the technical, organisational and cultural challenges to successful e-mail management and longer-term curation.

    Mobile support in CSCW applications and groupware development frameworks

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    Computer Supported Cooperative Work (CSCW) is an established subset of the field of Human Computer Interaction that deals with the how people use computing technology to enhance group interaction and collaboration. Mobile CSCW has emerged as a result of the progression from personal desktop computing to the mobile device platforms that are ubiquitous today. CSCW aims to not only connect people and facilitate communication through using computers; it aims to provide conceptual models coupled with technology to manage, mediate, and assist collaborative processes. Mobile CSCW research looks to fulfil these aims through the adoption of mobile technology and consideration for the mobile user. Facilitating collaboration using mobile devices brings new challenges. Some of these challenges are inherent to the nature of the device hardware, while others focus on the understanding of how to engineer software to maximize effectiveness for the end-users. This paper reviews seminal and state-of-the-art cooperative software applications and development frameworks, and their support for mobile devices

    Exploiting data semantics to discover, extract, and model web sources

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    We describe DEIMOS, a system that automatically discovers and models new sources of information. The system exploits four core technologies developed by our group that makes an end-to-end solution to this problem possible. First, given an example source, DEIMOS finds other similar sources online. Second, it invokes and extracts data from these sources. Third, given the syntactic structure of a source, DEIMOS maps its inputs and outputs to semantic types. Finally, it infers the source’s semantic definition, i.e., the function that maps the inputs to the outputs. DEIMOS is able to successfully automate these steps by exploiting a combination of background knowledge and data semantics. We describe the challenges in integrating separate components into a unified approach to discovering, extracting and modeling new online sources. We provide an end-toend validation of the system in two information domains to show that it can successfully discover and model new data sources in those domains. 1

    A security analysis of email communications

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    The objective of this report is to analyse the security and privacy risks of email communications and identify technical countermeasures capable of mitigating them effectively. In order to do so, the report analyses from a technical point of view the core set of communication protocols and standards that support email communications in order to identify and understand the existing security and privacy vulnerabilities. On the basis of this analysis, the report identifies and analyses technical countermeasures, in the form of newer standards, protocols and tools, aimed at ensuring a better protection of the security and privacy of email communications. The practical implementation of each countermeasure is evaluated in order to understand its limitations and identify potential technical and organisational constrains that could limit its effectiveness in practice. The outcome of the above mentioned analysis is a set of recommendations regarding technical and organisational measures that when combined properly have the potential of more effectively mitigating the privacy and security risks of today's email communications.JRC.G.6-Digital Citizen Securit

    Development of Online Course System and an Open Access Online Repository

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    This Project was divided in to two phases: the first phase comprising of development of an online course system for the institute with the help of moodle. Moodle( modular object oriented dynamic learning environment) is an open source software package for producing internet-based courses and web sites. It's an ongoing development project designed to support a social Constructionist framework of education. Moodle is provided freely as Open Source software (under the GNU Public License). Basically this means Moodle is copyrighted, but that we have additional freedoms of improvising the source code. The 2nd Phase of the project was that of deployment of an open access online repository system using E-prints. EPrints is an open source software package for building open access repositories that are compliant with the Open Archives Initiative Protocol for Metadata Harvesting. It shares many of the features commonly seen in Document Management systems, but is primarily used for institutional repositories and scientific journals. EPrints has been developed at the University of Southampton School of Electronics and Computer Science and released under a GPL license

    Melis: an incremental method for the lexical annotation of domain ontologies

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    In this paper, we present MELIS (Meaning Elicitation and Lexical Integration System), a method and a software tool for enabling an incremental process of automatic annotation of local schemas (e.g. relational database schemas, directory trees) with lexical information. The distinguishing and original feature of MELIS is the incremental process: the higher the number of schemas which are processed, the more background/domain knowledge is cumulated in the system (a portion of domain ontology is learned at every step), the better the performance of the systems on annotating new schemas.MELIS has been tested as component of MOMIS-Ontology Builder, a framework able to create a domain ontology representing a set of selected data sources, described with a standard W3C language wherein concepts and attributes are annotated according to the lexical reference database.We describe the MELIS component within the MOMIS-Ontology Builder framework and provide some experimental results of ME LIS as a standalone tool and as a component integrated in MOMIS
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