262 research outputs found

    Research and development of enhanced, integrated and accessible flow metering software for industry.

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    This project was an investigation to find improvements required in the delivery of software for the flow metering industry. The project has resulted in the repackaging of existing software using appropriate technologies. This included developing software that is accessible via the web and extending functionality whereby a user can import and export information in a variety of data formats. The software was successfully revised and is now commercially accessible to the flow metering industry. The project was performed in the context of a KTP (Knowledge Transfer Partnership) programme with academic supervision provided by TUV NEL (the academic partner) on the premises of KELTON® (the commercial partner) who provided day-to-day project management supervision. The project was in collaboration between the two organisations with the joint aims of facilitating knowledge transfer between the organisations and enhancing the market performance of the commercial partner. The main objective of the study was to gain a full understanding of the needs of the flow metering industry in terms of software and delivery via web or standalone application. Web based applications are new to KELTON® so it was necessary to investigate the methods of delivery. The work concentrated on investigating techniques to modularise code, allowing flexible access to data between applications and on data presentation. iv At an early stage of the project an online market survey program was developed and appropriate questions were used to get customer feedback. The results were analysed and used to prioritise work. Following the review, the current software architecture was found to be unsuitable so new approaches were investigated. The software was created using an n-tier architecture which is a method of splitting common code into separate components. Web based applications were found to be slower than standalone applications. However, web applications benefited from not having to fully install software on individual user PCs therefore allowing access from anywhere that users have access to the network

    Materials technology advancement program for expandable manned space structures Final report

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    Composite materials tests for expandable manned space structures including flammability, micrometeoroid impact, thermal shock, and tear, puncture, and fungus resistanc

    Performance evaluation of eXtended sparse linearization in GF(2) and GF(28)

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    XSL (eXtended Sparse Linearization) is a recent algebraic attack aimed at the Advanced Encryption Standard. In order to shed some light into the behavior of the algorithm, which is largely unknown, we have studied XSL on equation systems with variables interpreted either as bits or bytes. The algorithm solves byte-systems much faster than it does bit-systems, which promts us to suggest that if a more compact representation of equation systems can be found, such as one where the variables are 8-byte blocks, or even a more generalized form of 8n-byte blocks, it may be possible to increase the speed of XSL dramatically

    Heavy flavours

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    The paper introduces the selection of new results on heavy flavours presented at the QCD and High Energy Interactions section of the XLIIIth ``Rencontres de Moriond'' conference.Comment: Talk given at the QCD section of "Rencontres de Moriond

    Computational and Algebraic Aspects of the Advanced Encryption Standard

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    Abstract. The new Advanced Encryption Standard (AES) has been recently selected by the US government to replace the old Data Encryption Standard (DES) for protecting sensitive official information. Due to its simplicity and elegant algebraic structure, the choice of the AES algorithm has motivated the study of a new approach to the analysis of block ciphers. While conventional methods of cryptanalysis (e.g. differential and linear cryptanalysis) are usually based on a “statistical ” approach, where an attacker attempts to construct statistical patterns through many interactions of the cipher, the so-called algebraic attacks exploit the intrinsic algebraic structure of a cipher. More specifically, the attacker expresses the encryption transformation as a set of multivariate polynomial equations and attempts to recover the encryption key by solving the system. In this paper we consider a number of algebraic aspects of the AES, and examine a few computational and algebraic techniques that could be used in the cryptanalysis of cipher. We show how one can express the cipher as a very large, though surprisingly simple, system of multivariate quadratic equations over the finite field F 2 8, and consider some approaches that can be used to solve this system

    Towards a multimedia formatting vocabulary

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    Time-based, media-centric Web presentations can be described declaratively in the XML world through the development of languages such as SMIL. It is difficult, however, to fully integrate them in a complete document transformation processing chain. In order to achieve the desired processing of data-driven, time-based, media-centric presentations, the text-flow based formatting vocabularies used by style languages such as XSL, CSS and DSSSL need to be extended. The paper presents a selection of use cases which are used to derive a list of requirements for a multimedia style and transformation formatting vocabulary. The boundaries of applicability of existing text-based formatting models for media-centric transformations are analyzed. The paper then discusses the advantages and disadvantages of a fully-fledged time-based multimedia formatting model. Finally, the discussion is illustrated by describing the key properties of the example multimedia formatting vocabulary currently implemented in the back-end of our Cuypers multimedia transformation engine

    Survey and Benchmark of Block Ciphers for Wireless Sensor Networks

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    Cryptographic algorithms play an important role in the security architecture of wireless sensor networks (WSNs). Choosing the most storage- and energy-efficient block cipher is essential, due to the facts that these networks are meant to operate without human intervention for a long period of time with little energy supply, and that available storage is scarce on these sensor nodes. However, to our knowledge, no systematic work has been done in this area so far.We construct an evaluation framework in which we first identify the candidates of block ciphers suitable for WSNs, based on existing literature and authoritative recommendations. For evaluating and assessing these candidates, we not only consider the security properties but also the storage- and energy-efficiency of the candidates. Finally, based on the evaluation results, we select the most suitable ciphers for WSNs, namely Skipjack, MISTY1, and Rijndael, depending on the combination of available memory and required security (energy efficiency being implicit). In terms of operation mode, we recommend Output Feedback Mode for pairwise links but Cipher Block Chaining for group communications

    Analysis of the XSL Attack

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    In this paper, we examine the algebraic XSL attack on the Advanced Encryption Standard (AES). We begin with a brief introduction and we present an overview of AES, then, in Section 3, we present the algebraic attack on ciphers like AES, following with the XL and XSL algorithms in Section 4 and Section 5. Then, we present the XSL first and second attacks, also their aplicability on BES. We see how and if the algorithm has been improved since it firstly appeared. We conclude with Section 10
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