Search results for "Reliability engineering"
showing 10 items of 224 documents
Statistical analysis of RaptorQ failure probability applied to a data recovery software
2014
In this work, we have implemented a data recovery software integrating the most recent rateless codes, i.e., RaptorQ codes. Thanks to the above-mentioned software, it is possible to recover data loss occurring on several kinds of network conditions. We have performed a statistical analysis of failure probabilities at several configurations of RaptorQ parameters. We have found a good agreement with the theoretical values of a random linear fountain code over Galois Field GF(256). Moreover, we have shown that the probability of having a certain number of failed decoded source blocks - when sending a fixed size file - follows a Poisson distribution.
Optimization of Low-Cost Monitoring Systems for On-Site Earthquake Early-Warning of Critical Infrastructures
2020
In the last years, monitoring systems based on low-cost and miniaturized sensors (MEMS) revealed as a very successful compromise between the availability of data and their quality. Also applications in the field of seismic and structural monitoring have been constantly increasing in term of number and variety of functions. Among these applications, the implementation of systems for earthquake early warning is a cutting-edge topic, mainly for its relevance for the society as millions of peoples in various regions of the world are exposed to high seismic hazard. This paper introduces the optimization of an already established seismic (and structural) monitoring system, that would make it suit…
Qualitative models of equipment units and their use in automatic HAZOP analysis
2000
Abstract The use of qualitative models in a support system for HAZOP analyses, in connection with an algorithm for finding the causes and the consequences of variable deviations, is described. The models use several representation structures among which mini-trees constitute the most important from the logical-functional point of view. The models are conceived both for continuous and batch plants. For the latter procedures, regulating the use of equipment units are also modelled using similar structures while equipment units are considered in various phases of their functioning. A brief description of the prototype support system, in which the models are implemented, is also given.
Assessment of Human Capability, An Effective Tool to Obtain Confidence in the Visual Inspection Process
2018
Abstract To consistently produce high quality products, a quality management system must be practically implemented in every organization. One of its core instrument is to ensure the capability of the measurement systems, which are the basis for decisions regarding the behavior of the product critical quality characteristics. Base on requirements of the quality management system, a Measurement System Analysis should be conducted for all measurement system which are mentioned in the organization quality plan. Most problematic measurement system issues come from measuring discrete data, which are usually the result of human judgment (subjective decision) when categorizing products such as goo…
Measurement system analysis by attribute, an effective tool to ensure the quality of the visual inspection process within an organization
2019
A successful quality assurance program in any organization needs good measurement systems. The concept of measurement system refers to the manpower, machines, materials, methods and mother nature involved in obtaining measurements. Measurement system analysis (MSA) is a set of procedures which are used to determine the amount of variation due to the measurement system and if the measurement data are valid. Most problematic measurement system issues come when the results of a measurement system are qualitative values such as “pass” or “fail” (attribute data) rather than quantitative values (variable data). Because in industry many measurement systems deal with qualitative data, the assessmen…
Forecasting the Cell Temperature of PV Modules with an Adaptive System
2013
The need to reduce energy consumptions and to optimize the processes of energy production has pushed the technology towards the implementation of hybrid systems for combined production of electric and thermal energy. In particular, recent researches look with interest at the installation of hybrid system PV/T. To improve the energy performance of these systems, it is necessary to know the operating temperature of the photovoltaic modules. Furthermore, when photovoltaic (PV) systems replace the traditional building envelope materials and they are fully integrated (building integrated photovoltaic (BIPV)), it is very important to correctly assess their thermal behaviour. The determination of …
Electronic noses : specify or disappear
2000
Abstract When the quality control is achieved by using GC or GC/MS, the apparatus must comply with the applicable norms, but what about “electronic noses”? End users demand for formal specifications for selectivity, sensitivity, repeatability and sample throughput. The behavioural modelling of electronic olfactometers may provide specifications for these required parameters. This will allow both the measure itself, and evaluate the influence of the experimental errors on the sample classification. Users may expect to find a methodology allowing the performances of systems to be checked before any final decision and during routine use. We have demonstrated that the system sensitivity and log…
PQ Metrics Implementation on Low Cost Smart Metering Platforms. A Case Study Analysis
2018
The increasing interest on the quality of the energy supplied and generated in distribution networks is raising the need of distributed power quality (PQ) measurements. To allow such capabilities with cost effective metering solutions, this paper wants to investigate the feasibility of using smart meters, already installed for energy billing, also for power quality monitoring. To this aim, an electronic board (based on STCOMET metrology device), already used in many energy meters of different countries, has been selected as case study platform. The manufacturer firmware of this board was essentially aimed at implementing energy meter metrics and power line communications functionalities. In…
Maximizing energy transfer and RES integration using dynamic thermal rating
2019
Abstract The production of electricity from wind and other renewable sources is rapidly increasing all over the world, causing significant changes in the management of electrical systems. The current structural asset is not adequate to manage this growing generation of energy. The hypothesis of construction of new power lines would mean taking into consideration economic, political and social problems. The following paper reports the experience gained by the Italian TSO, Terna S.p.A, on the use of the DTR (Dynamic Thermal Rating), which is able to dynamically calculate the real transport capacity of an overhead power line. The results obtained are encouraging as they show how it is possible…
A Pattern Recognition Approach for Peak Prediction of Electrical Consumption
2014
Predicting and mitigating demand peaks in electrical networks has become a prevalent research topic. Demand peaks pose a particular challenge to energy companies because these are difficult to foresee and require the net to support abnormally high consumption levels. In smart energy grids, time-differentiated pricing policies that increase the energy cost for the consumers during peak periods, and load balancing are examples of simple techniques for peak regulation. In this paper, we tackle the task of predicting power peaks prior to their actual occurrence in the context of a pilot Norwegian smart grid network.