Search results for " Reliability"
showing 10 items of 557 documents
Hypervisor-based Protection of Code
2019
The code of a compiled program is susceptible to reverse-engineering attacks on the algorithms and the business logic that are contained within the code. The main existing countermeasure to reverse-engineering is obfuscation. Generally, obfuscation methods suffer from two main deficiencies: 1) the obfuscated code is less efficient than the original and 2) with sufficient effort, the original code may be reconstructed. We propose a method that is based on cryptography and virtualization. The most valuable functions are encrypted and remain inaccessible even during their execution, thus preventing their reconstruction. A specially crafted hypervisor is responsible for decryption, execution, a…
Krill herd algorithm-based neural network in structural seismic reliability evaluation
2018
ABSTRACTIn this research work, the relative displacement of the stories has been determined by means of a feedforward Artificial Neural Network (ANN) model, which employs one of the novel methods for the optimization of the artificial neural network weights, namely the krill herd algorithm. For the purpose of this work, the area, elasticity, and load parameters were the input parameters and the relative displacement of the stories was the output parameter. To assess the precision of the feedforward (FF) model optimized using the Krill Herd Optimization (FF-KH) algorithm, comparison of results has been performed relative to the results obtained by the linear regression model, the Genetic Alg…
Identification of differential risk hotspots for collision and vehicle type in a directed linear network
2019
Traffic accidents can take place in very different ways and involve a substantially distinct number and types of vehicles. Thus, it is of interest to know which parts of a road structure present an overrepresentation of a specific type of traffic accident, specially for some typologies of collisions and vehicles that tend to trigger more severe consequences for the users being involved. In this study, a spatial approach is followed to estimate the risk that different types of collisions and vehicles present in the central area of Valencia (Spain), considering the accidents observed in this city during the period 2014-2017. A directed spatial linear network representing the non-pedestrian ro…
Error mitigation using RaptorQ codes in an experimental indoor free space optical link under the influence of turbulence
2015
In free space optical (FSO) communications, several factors can strongly affect the link quality. Among them, one of the most important impairments that can degrade the FSO link quality and its reliability even under the clear sky conditions consists of optical turbulence. In this work, the authors investigate the generation of both weak and moderate turbulence regimes in an indoor environment to assess the FSO link quality. In particular, they show that, due to the presence of the turbulence, the link experiences both erasure errors and packet losses during transmission, and also compare the experimental statistical distribution of samples with the predicted Gamma Gamma model. Furthermore,…
Persistent software transactional memory in Haskell
2021
Emerging persistent memory in commodity hardware allows byte-granular accesses to persistent state at memory speeds. However, to prevent inconsistent state in persistent memory due to unexpected system failures, different write-semantics are required compared to volatile memory. Transaction-based library solutions for persistent memory facilitate the atomic modification of persistent data in languages where memory is explicitly managed by the programmer, such as C/C++. For languages that provide extended capabilities like automatic memory management, a more native integration into the language is needed to maintain the high level of memory abstraction. It is shown in this paper how persiste…
A risk evaluation framework for the best maintenance strategy: the case of a marine salt manufacture firm
2020
Highlights • This paper proposes a MCDM framework to support risk evaluation for maintenance activities. • The ANP is proposed to select the best maintenance strategy on the basis of real systems’ features. • The ELECTRE III is used to prioritise the main risks related to the interventions of the selected maintenance policy. • The proposed framework is applied to a core subsystem of a real-world marine salt manufacture firm.
Statistics-driven Development of OBD Systems: An Overview
2006
Automotive on-board diagnostic (OBD) systems are designed to keep critical components under control during vehicle functioning, and to alert the driver in case of severe malfunctions. OBD systems aimed at reducing polluting emissions are mandatory on new motor vehicles. Some research projects conducted in cooperation between universities and the automotive industry have been quite successful in terms of knowledge advancement and industrial gain. An updated overview of the adopted methodologies and results obtained are given in this article. Such results can be valuable for both theorists and practitioners, since they witness the use of statistics as a powerful catalyst of technical progress…
A statistical monitoring approach for automotive on-board diagnostic systems
2007
The current generation of vehicle models are increasingly being equipped with on-board diagnostic (OBD) systems aimed at assessing the ‘state of health’ of important anti-pollution subsystems and components. In order to promptly diagnose and fix quality and reliability problems that may potentially affect such complex diagnostic systems, even during advanced development prior to mass production, some vehicle prototypes undergo a testing phase under realistic conditions of use (a mileage accumulation campaign). The aim of this work is to set up a statistical tool for improving the reliability of the OBD system by monitoring its operation during the mileage accumulation campaign of a new vehi…
The Elephant in the Machine: Proposing a New Metric of Data Reliability and its Application to a Medical Case to Assess Classification Reliability
2020
In this paper, we present and discuss a novel reliability metric to quantify the extent a ground truth, generated in multi-rater settings, as a reliable basis for the training and validation of machine learning predictive models. To define this metric, three dimensions are taken into account: agreement (that is, how much a group of raters mutually agree on a single case)
Ranking of occupational health and safety risks by a multi-criteria perspective: Inclusion of human factors and application of VIKOR
2021
Nowadays, the Occupational Health and Safety (OHS) is more and more recognized as a crucial process to be properly managed and continuously improved by every organization. Primarily addressed to prevent workers’ injuries and diseases, it positively impacts on productivity, competitiveness and reputation as well as it con-tributes to cost savings in general. OHS management is grounded upon the risk assessment results, on the basis of which defining corrective measures to be taken to reduce risks to acceptable values. In this regard, the paper proposes a Multi-Criteria Decision Making (MCDM) based methodology addressed to the occupational risks prioritization. In order to overcome the shortco…