Search results for "SAF"
showing 10 items of 2183 documents
A Dempster-Shafer Theory-based approach to the Failure Mode, Effects and Criticality Analysis (FMECA) under epistemic uncertainty: application to the…
2017
Abstract Failure Mode and Effects Analysis (FMEA) is a safety and reliability analysis tool widely used for the identification of system/process potential failures, their causes and consequences. When aimed at the failure modes prioritization, FMEA is named Failure Mode, Effects and Criticality Analysis (FMECA). In the latter case, failure modes are commonly prioritized by means of the Risk Priority Number (RPN) that has been widely criticized to have several shortcomings. Firstly, in the presence of multiple experts supplying different and uncertain judgments on risk parameters, RPN is not able to deal with such a kind of information. Therefore, the present paper proposes the Dempster-Shaf…
Capacity and safety analysis of hard-shoulder running (HSR). A motorway case study
2016
Abstract Operational motorway conditions can be improved by introducing traffic flow management and control systems, such as ramp metering (RM), high occupancy vehicle (HOV) lanes, real-time variable speed limits (VSLs), reversible lanes (RL), automated highway systems (AHS) and hard-shoulder running (HSR). The effects of such devices need to be examined in terms of capacity and safety. This paper examines the case study of the Italian motorway A22, which is supposed to be equipped with an HSR system implemented along 128 km in order to reduce congestion with consequent improvement in levels of service (LOS). We studied the traffic processes (capacity, flow distribution between lanes, relia…
Identifying causes, dynamics and consequences of work accidents in forest operations in an alpine context
2016
Abstract In a sustainable perspective, where wood harvesting and use perfectly respond to environmental needs, social sustainability and related health and safety of forest workers cannot be disregarded. The aim of this study was the analysis of the accidents records in public companies in the Province of Trento, in Northern Italy, regarding forest operations in the period 1995–2013. Several information were available thanks to the up-to-date accident books compiled by each company. With an average Frequency index in the examined period of 88 injuries per million hours worked, forest operations were confirmed as one of the most dangerous works along all productive sectors. Monday had a sign…
An imprecise Fault Tree Analysis for the estimation of the Rate of OCcurrence Of Failure (ROCOF)
2013
Abstract The paper proposes an imprecise Fault Tree Analysis in order to characterize systems affected by the lack of reliability data. Differently from other research works, the paper introduces a classification of basic events into two categories, namely Initiators and Enablers . Actually, in real industrial systems some events refer to component failures or process parameter deviations from normal operating conditions ( Initiators ), whereas others refer to the functioning of safety barriers to be activated on demand ( Enablers ). As a consequence, the output parameter of interest is not the classical probability of occurrence of the top event, but its Rate of OCcurrence (ROCOF) over a s…
A Simple Method for Evaluating Ground-Fault Current Transfer at the Transition Station of a Combined Overhead-Cable Line
2008
When a substation is fed by a combined overhead-cable transmission line, a significant part of the ground fault current flows through cable sheaths and is discharged into the soil at the transition station where cables are connected to the overhead line. Such a phenomenon, known as ldquofault application transfer,rdquo may result in high ground potentials at the transition station which may cause shocks and equipment damage. The scope of this paper is to present new analytic formulas which can be used for the direct calculation of the fault current transferred at the transition station and its ground potential rise as well as the substation earth current. The proposed formulas allow evaluat…
Working Environment in the New EU Member State of Lithuania: Examining a ‘Worst Case’ Example
2008
Using recent survey data from Lithuania, it is suggested that post-communist countries such as Lithuania, admittedly a 'worst case' example, have specific legacies of serious health and safety problems. On a range of general health and occupational safety and health indicators, some three years after joining the European Union, Lithuania is currently a poor performer, and on key indicators the poorest in the European Union. Yet, formally, Lithuania has comprehensive health and safety legislation in line with EU requirements. Survey data suggest, however, a work regime of intensification and an absence of a participative working environment in which employees have a 'voice' in the safety man…
The New Nino Capability Index for Dynamic Process Capability Analysis
2013
The process capability analysis is a crucial activity to evaluate if the process outcome meets the design specifications. Classically, such analysis is performed by verifying the in-control condition of the process and evaluating suitable capability indices, by assuming the process in-control steady-state condition. However, the in-control period of the process characterizes only a part of the system functioning cycle, the one with the lower defective rate. In particular, the system functioning cycle is also characterized by the out-of-control period, during which a greater defective rate is produced, and such increasing is not considered by the widely adopted capability indices. As consequ…
Fundamental period of infilled reinforced concrete frame structures
2016
AbstractThe fundamental period of vibration appears to be one of the most critical parameters for the seismic design and assessment of structures. In the present paper, the results of a large-scale analytical investigation on the parameters that affect the fundamental period of reinforced concrete structures are presented. The influence of the number of storeys, the number of spans, the span length, the infill wall panel stiffness and the percentage of openings within the infill panel on the fundamental period of infilled RC frames was investigated. Based on these results, a regression analysis is applied in order to propose a new empirical equation for the estimation of the fundamental per…
Situation Understanding for Operational Art in Cyber Operations
2016
This paper presents a theoretically motivated framework and methodology that has been designed for finding out the emergent phenomena and information needs for planning and decision-making. The approach is based on complexity thinking, system modeling, communication and cognition philosophy, social system theories and content analysis research technique. It provides results with the analysis of quite small sets of information. The paper demonstrates the approach with a case study. The study was performed in an international cyber experiment of the Multinational Capability Development Campaign (MCDC) 2013-2014. The case study shows that the proposed approach is plausible for increasing under…
Analysis of pipeline accidents in the United States from 1968 to 2009
2014
Pipelines are responsible for the transportation of a significant portion of the U.S. energy supply. Unfortunately, pipeline failures are common and the consequences can be catastrophic. Drawing on data from the Pipeline and Hazardous Materials Safety Administration (PHMSA) that covers approximately 40,000 incidents from 1968 to 2009, this paper explores the trends, causes and consequences of natural gas and hazardous liquid pipeline accidents. The analysis indicates that fatalities and injuries from pipeline accidents are generally decreasing over time, while property damage and, in some cases, the numbers of incidents are increasing over time. In five of the ten cases considered in this p…