Search results for "Reliability engineering"

Energy Conscious Building Design

1987

Since the beginning of energy crisis many design tools have been developed in order to enable the designer to cope with energy consumption in buildings. These tools are of different kind: from very sophisticated simulation models to simplified (often too much) methods. Each of them offers various advantages and disadvantages, and it is up to the designer to choose among them.

Sleep assessment devices: types, market analysis, and a critical view on accuracy and validation

2019

[EN] Introduction: Sleep assessment devices are essential for the detection, diagnosis, and monitoring of sleep disorders. This paper provides a state-of-the-art review and comparison of sleep assessment devices and a market analysis. Areas covered: Hardware devices are classified into contact and contactless devices. For each group, the underlying technologies are presented, paying special attention to their limitations. A systematic literature review has been carried out by comparing the most important validation studies of sleep tracking devices in terms of sensitivity and specificity. A market analysis has also been carried out in order to list the most used, best-selling, and most high…

The Effect of Process Evolution on Capability Study

1996

In today manufacturing scenario the trend to produce with lower and lower tolerance and continuously decrease the defectives rate seems to be irreversible. Then the evaluation of system performances is essential to determine if the process is able to respect our tolerances. With the classical approach this evaluation is realised by considering the process in the in control state and evaluating the capability indices and, consequently, the defectives rate. In this paper the evolution of the process is considered in terms of the mean out-of-control-time, and the real defective rate is evaluated by proposing a new capability index.

Development of a big data bank for PV monitoring data, analysis and simulation in COST Action 'PEARL PV'

2019

COST Action entitled PEARL PV aims at analyzing data of monitored PV systems installed all over Europe to quantitatively evaluate the long-term performance and reliability of these PV systems. For this purpose, a data bank is being implemented that can contain vast amounts of data, which will enable systematic performance analyses in combination with simulations. This paper presents the development process of this data bank.

A Survey of the Reliability Methods Approach in Some Codes for Structural Design

1992

Structural codes are documents which are subject to periodic revision and amendment. The main reason of this is due to developments from theoretical and experimental research. The rules and codes for the design of civil engineering structures which are prepared or which are under preparation by different regional and international organizations are under review. Similarities and differences in the approaches to the reliability — oriented concept of calculated safety verifications on the design stages prescribed in the codes (available to author) are presented in this paper.

Fuzzy FMECA analysis of radioactive gas recovery system in the SPES experimental facility

2021

Abstract Selective Production of Exotic Species is an innovative plant for advanced nuclear physic studies. A radioactive beam, generated by using an UCx target-ion source system, is ionized, selected and accelerated for experimental objects. Very high vacuum conditions and appropriate safety systems to storage exhaust gases are required to avoid radiological risk for operators and people. In this paper, Failure Mode, Effects, and Criticality Analysis of a preliminary design of high activity gas recovery system is performed by using a modified Fuzzy Risk Priority Number to rank the most critical components in terms of failures and human errors. Comparisons between fuzzy approach and classic…

Energy Consumption Management of the Automated Self-service Centre’s Storage Module: Models and Simulations

2015

Enhanced islanding detection in smart interface protection systems of distributed generation

2021

The widespread presence of distributed generators (DGs) and storage systems (DSSs) in electricity grids has increased the risk of islanding occurrence. This phenomenon must be suitably managed by Distribution System Operators (DSO), in order to avoid adverse situations, in terms of grid-protection problems, equipment damage, safety hazards, power quality problems and so on. Currently anti-islanding protection functions are handled by interface protection systems (IPSs), which are built in accordance with relevant standards for DGs and DSSs connection to power systems. However, some problems may occur in case of operation within the so-called non detection zone (NDZ). This paper presents an …

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…

Critical analysis of conventional thermoeconomic approaches to the diagnosis of multiple faults in air conditioning units: Capabilities, drawbacks an…

2013

Abstract Faults diagnosis in air conditioning systems is a crucial activity, since malfunctions may induce heavy degradation of performance. Among the available techniques, thermoeconomic diagnosis has played a marginal role due to the difficulties encountered when applying the methodology to refrigeration plants. In this paper a critical analysis on capabilities and limits of thermoeconomic diagnosis is proposed. The reference plant is a 120 kWc air-cooled air conditioning system; a simulator is used to evaluate thermodynamic data under normal and faulty conditions, setting up “virtual experiments” to simulate each fault. Five malfunctions are imposed, either individually or simultaneously…