143,155 research outputs found

    FRAM for systemic accident analysis: a matrix representation of functional resonance

    Get PDF
    Due to the inherent complexity of nowadays Air Traffic Management (ATM) system, standard methods looking at an event as a linear sequence of failures might become inappropriate. For this purpose, adopting a systemic perspective, the Functional Resonance Analysis Method (FRAM) originally developed by Hollnagel, helps identifying non-linear combinations of events and interrelationships. This paper aims to enhance the strength of FRAM-based accident analyses, discussing the Resilience Analysis Matrix (RAM), a user-friendly tool that supports the analyst during the analysis, in order to reduce the complexity of representation of FRAM. The RAM offers a two dimensional representation which highlights systematically connections among couplings, and thus even highly connected group of couplings. As an illustrative case study, this paper develops a systemic accident analysis for the runway incursion happened in February 1991 at LAX airport, involving SkyWest Flight 5569 and USAir Flight 1493. FRAM confirms itself a powerful method to characterize the variability of the operational scenario, identifying the dynamic couplings with a critical role during the event and helping discussing the systemic effects of variability at different level of analysis

    Deterministic and Probability Analysis of Paper Machine Vibration Impact to the Structure Safety and Human Comfort

    Get PDF
    This paper describes the probability and sensitivity analysis of the concrete frame and paper machine interaction. On the base of the experimental results, the calculation FEM model was verified. The uncertainties of the loads level, the material properties and other influences following the inaccuracy of the calculated model and numerical methods were considered in the approximation method RSM

    Fire protection of emergency electrical devices: effect on the level of risk. Case study of rail tunnel

    Get PDF
    The paper proposes the main results obtained from the Quantitative Risk Analysis developed on an existing tunnel, according to the Ministerial Decree "Safety of railway tunnels" (October 28 2005). The fire produces the most severe scenario among the possible emergencies in confined area, thus the regulations in Europe and in Italy (Technical Specifications for Interoperability, Decision December 20th 2007, Ministerial Decree October 28th 2005) obligate to direct adoption of measures and devices for prevention and protection to reduce the probability of occurrence of this specific critical scenario and the containment of the fire effects. To mitigate the damage, the difficulty of providing an effective external rescue in a short time involves supplementary safety measures aimed at improving the process of self-rescue

    Timed Fault Tree Models of the China Yongwen Railway Accident

    Get PDF
    Safety is an essential requirement for railway transportation. There are many methods that have been developed to predict, prevent and mitigate accidents in this context. All of these methods have their own purpose and limitations. This paper presents a new useful analysis technique: timed fault tree analysis. This method extends traditional fault tree analysis with temporal events and fault characteristics. Timed Fault Trees (TFTs) can determine which faults need to be eliminated urgently, and it can also provide a safe time window to repair them. They can also be used to determine the time taken for railway maintenance requirements, and thereby improve maintenance efficiency, and reduce risks. In this paper, we present the features and functionality of a railway transportation system based on timed fault tree models. We demonstrate the applicability of our framework via a case study of the China Yongwen line railway accident

    Study of airborne science experiment management concepts for application to space shuttle. Volume 1: Executive summary

    Get PDF
    The management concepts and operating procedures are documented as they apply to the planning of shuttle spacelab operations. Areas discussed include: airborne missions; formulation of missions; management procedures; experimenter involvement; experiment development and performance; data handling; safety procedures; and applications to shuttle spacelab planning. Characteristics of the airborne science experience are listed, and references and figures are included

    Optimal control of the heave motion of marine cable subsea-unit systems

    Get PDF
    One of the key problems associated with subsea operations involving tethered subsea units is the motions of support vessels on the ocean surface which can be transmitted to the subsea unit through the cable and increase the tension. In this paper, a theoretical approach for heave compensation is developed. After proper modelling of each element of the system, which includes the cable/subsea-unit, the onboard winch, control theory is applied to design an optimal control law. Numerical simulations are carried out, and it is found that the proposed active control scheme appears to be a promising solution to the problem of heave compensation

    Alternative sweetener from curculigo fruits

    Get PDF
    This study gives an overview on the advantages of Curculigo Latifolia as an alternative sweetener and a health product. The purpose of this research is to provide another option to the people who suffer from diabetes. In this research, Curculigo Latifolia was chosen, due to its unique properties and widely known species in Malaysia. In order to obtain the sweet protein from the fruit, it must go through a couple of procedures. First we harvested the fruits from the Curculigo trees that grow wildly in the garden. Next, the Curculigo fruits were dried in the oven at 50 0C for 3 days. Finally, the dried fruits were blended in order to get a fine powder. Curculin is a sweet protein with a taste-modifying activity of converting sourness to sweetness. The curculin content from the sample shown are directly proportional to the mass of the Curculigo fine powder. While the FTIR result shows that the sample spectrum at peak 1634 cm–1 contains secondary amines. At peak 3307 cm–1 contains alkynes
    • …
    corecore