990 resultados para Architecture, European


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Architecture Description Languages (ADLs) have emerged in recent years as a tool for providing high-level descriptions of software systems in terms of their architectural elements and the relationships among them. Most of the current ADLs exhibit limitations which prevent their widespread use in industrial applications. In this paper, we discuss these limitations and introduce ALI, an ADL that has been developed to address such limitations. The ALI language provides a rich and flexible syntax for describing component interfaces, architectural patterns, and meta-information. Multiple graphical architectural views can then be derived from ALI's textual notation.

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Very high speed and low area hardware architectures of the SHACAL-1 encryption algorithm are presented in this paper. The SHACAL algorithm was a submission to the New European Schemes for Signatures, Integrity and Encryption (NESSIE) project and it is based on the SHA-1 hash algorithm. To date, there have been no performance metrics published on hardware implementations of this algorithm. A fully pipelined SHACAL-1 encryption architecture is described in this paper and when implemented on a Virtex-II X2V4000 FPGA device, it runs at a throughput of 17 Gbps. A fully pipelined decryption architecture achieves a speed of 13 Gbps when implemented on the same device. In addition, iterative architectures of the algorithm are presented. The SHACAL-1 decryption algorithm is derived and also presented in this paper, since it was not provided in the submission to NESSIE. © Springer-Verlag Berlin Heidelberg 2003.

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The electronic storage of medical patient data is becoming a daily experience in most of the practices and hospitals worldwide. However, much of the data available is in free-form text, a convenient way of expressing concepts and events, but especially challenging if one wants to perform automatic searches, summarization or statistical analysis. Information Extraction can relieve some of these problems by offering a semantically informed interpretation and abstraction of the texts. MedInX, the Medical Information eXtraction system presented in this document, is the first information extraction system developed to process textual clinical discharge records written in Portuguese. The main goal of the system is to improve access to the information locked up in unstructured text, and, consequently, the efficiency of the health care process, by allowing faster and reliable access to quality information on health, for both patient and health professionals. MedInX components are based on Natural Language Processing principles, and provide several mechanisms to read, process and utilize external resources, such as terminologies and ontologies, in the process of automatic mapping of free text reports onto a structured representation. However, the flexible and scalable architecture of the system, also allowed its application to the task of Named Entity Recognition on a shared evaluation contest focused on Portuguese general domain free-form texts. The evaluation of the system on a set of authentic hospital discharge letters indicates that the system performs with 95% F-measure, on the task of entity recognition, and 95% precision on the task of relation extraction. Example applications, demonstrating the use of MedInX capabilities in real applications in the hospital setting, are also presented in this document. These applications were designed to answer common clinical problems related with the automatic coding of diagnoses and other health-related conditions described in the documents, according to the international classification systems ICD-9-CM and ICF. The automatic review of the content and completeness of the documents is an example of another developed application, denominated MedInX Clinical Audit system.

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At a time when the traditional major airlines have struggled to remain viable, the low-cost carriers have become the major success story of the European airline industry. This paper looks behind the headlines to show that although low-cost airlines have achieved much, they too have potential weaknesses and face a number of challenges in the years ahead. The secondary and regional airports that have benefited from low-cost carrier expansion are shown to be vulnerable to future changes in airline economics, government policy and patterns of air service. An analysis of routes from London demonstrates that the low-cost airlines have been more successful in some markets than others. To attractive and historically under-served leisure destinations in Southern Europe they have stimulated dramatic growth and achieved a dominant position. To major hub cities however they typically remain marginal players and to secondary points in Northern Europe their traffic has been largely diverted from existing operators. There is also evidence that the UK market is becoming saturated and new low-cost services are poaching traffic from other low-cost routes. Passenger compensation legislation and possible environmental taxes will hit the low-cost airline industry disproportionately hard. The high elasticities of demand to price in certain markets that these airlines have exploited will operate in reverse. One of the major elements of the low-cost business model involves the use of smaller uncongested airports. These offer faster turn-arounds and lower airport charges. In many cases, local and regional government has been willing to subsidise expansion of air services to assist with economic development or tourism objectives. However, recent court cases against Ryanair now threaten these financial arrangements. The paper also examines the catchment areas for airports with low-cost service. It is shown that as well as stimulating local demand, much traffic is captured from larger markets nearby through the differential in fare levels. This has implications for surface transport, as access to these regional airports often involves long journeys by private car. Consideration is then given to the feasibility of low-cost airlines expanding into the long-haul market or to regional operations with small aircraft. Many of the cost advantages are more muted on intercontinental services.

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Recommendations report produced as part of the EC-funded BESTUFS project on urban freight transport.

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Christoph Franz of Lufthansa recently identified Ryanair, easyJet, Air Berlin and Emirates as the company’s main competitors – gone are the days when it could benchmark itself against BA or Air France-KLM! This paper probes behind the headlines to assess the extent to which different airlines are in competition, using evidence from the UK and mainland European markets. The issue of route versus network competition is addressed. Many regulators have put an emphasis on the former whereas the latter, although less obvious, can be more relevant. For example, BA and American will cease to compete between London and Dallas Fort Worth if their alliance obtains anti-trust immunity but 80% of the passengers on this route are connecting at one or both ends and hence arguably belong to different markets (e.g. London-San Francisco, Zurich-Dallas, Edinburgh-New Orleans) which may be highly contested. The remaining 20% of local traffic is actually insufficient to support a single point to point service in its own right. Estimates are made of the seat capacity major airlines are offering to the local market as distinct from feeding other routes. On a sector such as Manchester–Amsterdam, 60% of KLM’s passengers are transferring at Schiphol as against only 1% of bmibaby’s. Thus although KLM operates 5 flights and 630 seats per day against bmibaby’s 2 flights and 298 seats, in the point to point market bmibaby offers more seats than KLM. The growth of the Low Cost Carriers (LCCs) means that competition increasingly needs to be viewed on city pair markets (e.g. London-Rome) rather than airport pair markets (e.g. Heathrow-Fiumicino). As the stronger LCCs drive out weaker rivals and mainline carriers retrench to their major hubs, some markets now have fewer direct options than existed prior to the low cost boom. Timings and frequencies are considered, in particular the extent to which services are a true alternative especially for business travellers. LCCs typically offer lower frequencies and more unsociable timings (e.g. late evening arrivals at remote airports) as they are more focused on providing the cheapest service rather than the most convenient schedule. Interesting findings on ‘monopoly’ services are presented (including alliances) - certain airlines have many more of these than others. Lufthansa has a significant number of sectors to itself whereas at the other extreme British Airways has direct competition on almost every route in its network. Ryanair and flybe have a higher proportion of monopoly routes than easyJet or Air Berlin. In the domestic US market it has become apparent since deregulation that better financial returns can come from dominating a large number of smaller markets rather than being heavily exposed in the major markets - which are hotly fought over. Regional niches that appear too thin for Ryanair to serve (with its all 189 seat 737-800 fleet) are identified. Fare comparisons in contrasting markets provide some insights to marketing and pricing strategies. Data sources used include OAG (schedules and capacity), AEA (traditional European airlines traffic by region), the UK CAA (airport, airline and route traffic plus survey information of passenger types) and ICAO (international route traffic and capacity by carrier). It is concluded that airlines often have different competitors depending on the context but in surprisingly many cases there are actually few or no direct substitutes. The competitive process set in train by deregulation of European air services in the 1990s is leading back to one of natural monopolies and oblique alternatives. It is the names of the main participants that have changed however!

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