Search results for " Mecca"
showing 10 items of 1035 documents
A hybrid multi-criteria approach to GPR image mining applied to water supply system maintenance
2018
[EN] Data processing techniques for Ground Penetrating Radar (GPR) image mining provide essential information to optimize maintenance management of Water Supply Systems (WSSs). These techniques aim to elaborate on radargrams in order to produce meaningful graphical representations of critical buried components of WSSs. These representations are helpful non-destructive evaluation tools to prevent possible failures in WSSs by keeping them adequately monitored. This paper proposes an integrated multi-criteria decision making (MCDM) approach to prioritize various data processing techniques by means of ranking their outputs, namely their resulting GPR image representations. The Fuzzy Analytic Hi…
An expert system for vineyard management based upon pervasive computer technologies
2009
Determining the optimal maturity level for performing viticulture operations and harvesting activities is a difficult task, because, depending on the variety, the climatic conditions and cultural practices, the phenologic maturation process occurs at different times. Recently, ubiquitous computing technologies allow an extremely precise and cost effective monitoring of environmental conditions by means of an RFID based sensor networks. The implementation of such technologies in vineyard management is nowadays under development, however, besides the possibility of gathering data, the need is perceived of developing decision support tools to fully exploit the potential opportunities of these …
ELECTRE III to dynamically support the decision maker about the periodic replacements configurations for a multi-component system
2013
The problem tackled by the present paper concerns the selection of the elements of a repairable and stochastically deteriorating multi-component system to replace (replacements configuration) during each scheduled and periodical system stop within a finite optimization cycle, by ensuring the simultaneous minimization of both the expected total maintenance cost and the system unavailability. To solve the considered problem, a combined approach between multi-objective optimization problem (MOOP) and multi-criteria decision making (MCDM) resolution techniques is proposed. In particular, the @e constraint method is used to single out the optimal Pareto frontier whereas the ELECTRE III multi-cri…
A Fuzzy Inference Expert System to Support the Decision of Deploying a Military Naval Unit to a Mission
2009
Naval military units are complex systems required to operate in fixed time frames in offshore tasks where maintenance operations are drastically limited. A failure during a mission is a critical event that can drastically influence the mission success. The decision of switching a unit to a mission hence requires complex judgments involving information about the health status of machineries and the environmental conditions. The present procedure aims to support the decision about switching a unit to a mission considering the vagueness and uncertainty of information by means of fuzzy theory and emulates the decision process of a human expert by means of a rule-based inference engine. A numeri…
A decision support system based on multisensor data fusion for sustainable greenhouse management
2018
The sustainable exploitation of natural resources is nowadays an important challenge for governments and institutions, considering the expected increase of the world population. In order to respond to this emergent criticality, the principles of green economy have been introduced in the European policy discussion to achieve a good compromise between the sustainability and the profitability of productions by increasing the efficiency of farming operations. Such approach poses some technical and financial challenges for small-sized enterprises because they generally do not possess adequate internal knowledge, nor they can acquire external expertise due to their budget restrictions. Decision S…
Laser Ultrasonics Inspection of Train Wheel - Evaluation of Optimized Setup
2021
In the railway field, the safety of passengers and the service life of train components are a crucial issue. For this reason, continuous periodic inspections by non-destructive techniques are required. Among these, ultrasonic tests are widely used in this field, even though the conventional ultrasound techniques have the disadvantage of requiring the disassembly of the wheels and of putting the train out of service. This procedure is expensive and time-consuming and can be neglected if non-contact ultrasonic techniques are used. In this work, the authors present an experimental research on some defects, artificially obtained on a railway wheel supplied by Trenitalia Spa, by adopting three d…
TAPPARELLA AVVOLGIBILE A SISTEMA DESMODROMICO
2017
La presente invenzione riguarda una tapparella avvolgibile a sistema desmodromico. La tapparella della presente invenzione è dotata di un meccanismo che consente l'apertura delle lamelle sfruttando il peso stesso della tapparella. L'apertura delle lamelle viene attuata grazie alla particolare geometria del meccanismo e mediante l'interazione tra le guide e le parti scorrevoli della tapparella. La sua geometria riesce a determinare l’apertura o la chiusura delle lamelle. The present invention relates to a roller shutter with a desmodromic-system. The shutter of the present invention is provided with a mechanism allowing the slats to be opened by exploiting the weight of the blind itself. The…
Electrochemical detection of uric acid and ascorbic acid using r-GO/NPs based sensors
2021
Abstract A sensitive and selective electrochemical sensor, based on reduced graphene oxide and gold nanoparticles obtained by simple co-electrodeposition, was developed for the detection of uric acid and ascorbic acid. Because of the electrochemical oxidation of both uric and ascorbic acid depending on the pH, the sensor performances were studied at different pH values. Excellent results were obtained for uric acid detection in a linear range from 10 to 500 µmol dm−3 with a sensitivity of 0.31 µA cm−2 µM−1. A limit of detection and quantification of 3.6 µM and 10.95 µmol dm−3, respectively, was calculated. Sensors showed good selectivity toward different interfering species present in the m…
Electrochemical detection of chloride ions using Ag-based electrodes obtained from compact disc
2022
Abstract In this work electrochemical sensors fabricated from compact disc material (waste or new) are used to quantify chloride ions in different types of samples. All three electrodes, working, counter, and pseudo-reference electrodes, were fabricated from the compact disc and directly used. Different parameters were studied in order to demonstrate the possibility of using this waste material for efficient and low-cost electrochemical sensors. Chloride sensing performance was evaluated using linear scan voltammetry as the detection technique. A sensitivity of 0.174 mA mM−1 cm−2 with a limit of detection of 20 μM and excellent selectivity against many interferents was observed. Selectivity…
NUMERICAL-EXPERIMENTAL METHOD FOR THE ANALYSIS OF RESIDUAL STRESSES IN COLD-EXPANDED HOLES
2012
Hole cold expansion is a technique widely used to improve the fatigue life of components with holes, e.g. bolted or riveted joints. As it has been demonstrated in literature by analytical, numerical and experimental analyses carried out by several authors, the compressive residual stresses introduced by the hole cold expansion have a beneficial influence on both the static and the fatigue strength of the treated component, because they reduce significantly the typical stress peaks around the hole due to stress concentration. In the literature, various analyses of the residual stresses introduced by the hole cold expansion have been performed by using several methods such as X-ray diffractio…