Search results for "Liability"
showing 10 items of 1754 documents
Profiling Safety Behaviors: Exploration of the Sociocognitive Variables that Best Discriminate Between Different Behavioral Patterns
2012
This study combines contributions from both safety climate literature and prominent social influence theories. It was developed to identify the combination of sociocognitive variables that differentiate between different profiles of safety behaviors. This empirical approach has hardly been explored in the literature on behavioral aspects related to safety. The research setting for this study was a transportation company (N= 356). The results of discriminant analysis showed that different combinations of dispositional and situational influences may lead to diverse profiles of compliance and proactive safety behaviors. Perceived behavioral control was revealed to be the variable that best dif…
Safety climate responses and the perceived risk of accidents in the construction industry
2008
The usefulness of safety climate as a diagnostic tool ought to reside in its ability to identify detailed and precise difficulties that can be considered critical to improving safety. This feature depends on the theoretical analysis of the agents and issues that should be included in safety climate statements. Safety climate can be analysed from the point of view of the agent that performs the safety response in question, by identifying four main safety agents (organization, supervisors, co-workers and worker) and five safety climate variables: the Organizational Safety Response (OSR), the Supervisors' Safety Response (SSR), the Co-Workers' Safety Response (CSR), the Worker Safety Response …
Reliability assessment of granular filters in embankment dams
2006
SUMMARY Empirical criteria have been used successfully to design filters of most embankment large dam projects throughout the world. However, these empirical rules are only applicable to a particular range of soils tested in laboratory and do not take into account the variability of the base material and filter particle sizes. In addition, it is widely accepted that the safety of fill dams is mainly dependent on the reliability of their filter performance. The work herein presented consists in a new general method for assessing the probability of fulfilling any empirical filter design criteria accounting for base and filter heterogeneity by means of first-order reliability methods (FORM), s…
DC link voltage swinging and load current unbalance in fault tolerant VSI. overview and compensation strategies
2015
The topic of this paper is the discussion on the performance of a three-phase fault tolerant inverter with particular attention to the underrated aspect of current unbalances occurring due to the DC link voltage fluctuates after the inverter reconfiguration. Capacitor voltage unbalance affects not only the average output voltage of the inverter, but also its performance. In fact, the inverter performance depends on the fluctuating DC-link voltage components rather than on the average DC-link voltage. After a brief analysis of the voltage fluctuation phenomena resulting from fault tolerant configuration and their effect on load current unbalance, the Authors consider different compensating p…
A Robustness Approach to Reliability
2012
Reliability of products is here regarded with respect to failure avoidance rather than probability of failure. To avoid failures, we emphasize variation and suggest some powerful tools for handling failures due to variation. Thus, instead of technical calculation of probabilities from data that usually are too weak for correct results, we emphasize the statistical thinking that puts the designers focus on the critical product functions. Making the design insensitive to unavoidable variation is called robust design and is handled by (i) identification and classification of variation, (ii) design of experiments to find robust solutions, and (iii) statistically based estimations of proper safe…
Probabilistic Approach to the Design of Photovoltaic Distributed Generation in Low Voltage Feeder
2006
This paper presents the probabilistic approach to the design of photovoltaic (PV) distributed generation (DG) and its impact on low voltage (LV) feeder. Monte Carlo simulation is used to predict solar radiation and load, and an exact method is used to solve the power flow. The method is tested on two study cases, and the results are compared with those from deterministic approach based on commonly used scenarios. The probabilistic approach is shown necessary to obtain the optimum PV rating based on technical constraints and different objectives, including accepting a reasonable risk when needed. The results also indicate that PV-DG in a realistic case will most probably improve the voltage …
Effects of double ground faults in Wind Farms collector cables
2015
Medium Voltage collector cables of Wind Farms have metal shields connected to the grounding systems of the towers and of the connection station. Thanks to this bonding, when a ground fault occurs, the fault current splits itself among all the grounding systems of the wind farm, this causing a reduction of the ground potential rise at the fault location. Nevertheless, in presence of double ground faults, very high ground potential rises occur at the two fault locations and safety against electric shock is not always assured. In order to study this issue, the paper presents a model for simulating in a simple way the effects of double ground faults occurring in Medium Voltage collectors of ext…
A new high accuracy software based resolver-to-digital converter
2004
Tracking resolver-to-digital conversion (R/D converter or simply RDC) has emerged as one of the most robust method for obtaining high resolution position and angular speed information from resolvers. In this paper a low cost software based RDC is presented. The main features are: high accuracy, simple set up, high reliability and stability and good performances. Some experimental results, showing the capabilities of the proposed system, are presented and discussed. An output signal comparison between the proposed RDC and a commercial encoder is also presented.
Real time assessment of hand-arm vibration system based on capacitive MEMS accelerometers
2012
Vibrations are a well known potential cause of health diseases and therefore constitute a main concern for the safety of workers in a large number of activities. In order to prevent health hazards, national and international institutions have issued laws and directives which establish recommended limits to the workers' exposure to vibrations during operations. Consequently, if the amount of adsorbed vibration exceeds the allowable daily limits the worker has to stop his job. Recent wireless sensing and communicating technologies can effectively be employed for such purpose, allowing to develop monitoring customized devices at affordable cost which could be easily employed during the workers…
Development of Diagnostic Systems for the Fault Tolerant Operation of Micro-Grids
2010
The progressive penetration level of Distributed Generation (DG) is destined to cause deep changes in the existing distribution networks no longer considered as passive terminations of the whole electrical system. A possible solution is the realization of small networks, namely the Micro-Grids, reproducing in themselves the structure of the main production and distribution of the electrical energy system. In order to gain an adequate reliability level of the micro-grids the individuation and the management of the faults with the goal of maintaining the micro-grid operation (fault tolerant operation) is quite important. In the present paper after the introduction of the aims of several diagn…