Search results for "Cryptography"
showing 10 items of 657 documents
Vertical relationships for the European railway industry
2001
Abstract A key question in the reform process of Europe's railway industry is the decision whether to opt for a market structure that vertically integrates infrastructure and operations, or for one that separates them. In making this decision, knowledge of the relationship between operating costs and the infrastructure is fundamental. For this purpose a translogarithmic cost function is estimated, including the multi-product nature of railway companies and a measurement of the value of the infrastructure. The results show that costs deriving from freight transport and from the infrastructure are complementary, while those deriving from passenger transport and from the infrastructure are sub…
Comparison of Studies on Mobile Phone Use and Risk of Tumors
2010
published results of ameta-analysis of studies on mobile phone use and risk of tumors. Intheir analysis, the authors included 23 case-control studies, covering abroad spectrum of tumor entities including uveal melanoma, testicu-lar cancer, parotid gland tumors, and brain tumors.However, the authors give no rationale for pooling these hetero-geneous, biologically rather diverse cancer sites, for which the local-ized exposure from the use of mobile phones is completely different.The key difference between this particular meta-analysis com-pared with earlier ones is the use of a quality score. The use of qualityscoreshasbeenreportedtobea“formofsubjectivitymasqueradingasobjectivity”andithasbeen…
Semi-automatic Quasi-morphological Word Segmentation for Neural Machine Translation
2018
This paper proposes the Prefix-Root-Postfix-Encoding (PRPE) algorithm, which performs close-to-morphological segmentation of words as part of text pre-processing in machine translation. PRPE is a cross-language algorithm requiring only minor tweaking to adapt it for any particular language, a property which makes it potentially useful for morphologically rich languages with no morphological analysers available. As a key part of the proposed algorithm we introduce the ‘Root alignment’ principle to extract potential sub-words from a corpus, as well as a special technique for constructing words from potential sub-words. We conducted experiments with two different neural machine translation sys…
Security Wireless Solution for Semantic Smart SCADA/DCS
2015
Journal spécialisé das industrie du gaz; International audience; We present the ability to detect and infiltrate semantic attacks a wireless radio network used in semantic (SCADA/DCS) systems, these attacks deny operators and automated systems the ability to safely and reliably monitor and control semantic sensors, semantic actuators, relays, and breakers. We presented in this work new security semantic wireless protocols as a secure communication support for these modern semantic wireless systems and a global security solution for interconnected (IT-SCADA) platforms.
Deriving scaling laws in geodynamics using adjoint gradients
2018
Abstract Whereas significant progress has been made in modelling of lithospheric and crustal scale processes in recent years, it often remains a challenge to understand which of the many model parameters is of key importance for a particular simulation. Determining this is usually done by manually changing the model input parameters and performing new simulations. For a few cases, such as for folding or Rayleigh-Taylor instabilities, one can use thick-plate stability analysis to derive scaling laws to obtain such insights. Yet, for more general cases, it is not straightforward to do this (apart from running many simulations). Here, we discuss a numerically cheaper approach to compute scalin…
Morphological Enhancement and Triangular Matching for Fingerprint Recognition
2008
Among the principal problems for realizing a robust Automated Fingerprint Identification System (AFIS) there are the images quality and matching algorithms. In this paper a fingerprint enhancement algorithm based on morphological filter and a triangular matching are introduced. The enhancement phase is based on tree steps: directional decomposition, morphological filter and composition. For the matching phase a global transformation to overcame the effects of rotation, displacement and deformation between acquired and stored fingerprint is performed using the number of similar triangular, having fingerprint minutiae as vertexes. The performance of the proposed approach has been evaluated on…
Checkpointing Workflows for Fail-Stop Errors
2017
International audience; We consider the problem of orchestrating the exe- cution of workflow applications structured as Directed Acyclic Graphs (DAGs) on parallel computing platforms that are subject to fail-stop failures. The objective is to minimize expected overall execution time, or makespan. A solution to this problem consists of a schedule of the workflow tasks on the available processors and of a decision of which application data to checkpoint to stable storage, so as to mitigate the impact of processor failures. For general DAGs this problem is hopelessly intractable. In fact, given a solution, computing its expected makespan is still a difficult problem. To address this challenge,…
Serial In-network Processing for Large Stationary Wireless Sensor Networks
2017
International audience; In wireless sensor networks, a serial processing algorithm browses nodes one by one and can perform different tasks such as: creating a schedule among nodes, querying or gathering data from nodes, supplying nodes with data, etc. Apart from the fact thatserial algorithms totally avoid collisions, numerous recent works have confirmed that these algorithms reduce communications andconsiderably save energy and time in large-dense networks. Yet, due to the path construction complexity, the proposed algorithmsare not optimal and their performances can be further enhanced. To do so, in the present paper, we propose a new serial processing algorithm that, in most of the case…
IMPACT OF TIMETABLE SYNCHRONIZATION ON HUB CONNECTIVITY OF EUROPEAN CARRIERS
2016
This paper evaluates the net impact of timetable synchronization on the connectivity of the key European carriers at their main hubs. We measure hub connectivity using a weighted connectivity score (WCS) that takes into account the number and the trip time related quality of flight connections. Based on WCS, we compare hub performance resulting from the existing schedule against a random expectati on calculated from multiple randomized schedule simulations. In each simulated schedule scenario we randomly vary the flight departure and arrival times within the operation hours at a hub and at outbound stations keeping all other flight parameters from the real schedule unchanged.We observe that…
Adaptive control of a class of strict-feedback time-varying nonlinear systems with unknown control coefficients
2018
Abstract In this paper, robust adaptive control of a class of strict-feedback nonlinear systems with unknown control directions is investigated. A novel Nussbaum-type function is developed and a key theorem is drawn which involves quantifying the addition of multiple Nussbaum functions with different control directions in a single inequality. Global stability of the closed-loop system and asymptotic stabilization of system output are proved. A simulation example is given to illustrate the effectiveness of the proposed control scheme.