Rasa Remenyte-Prescott

University of Nottingham | Notts · Resilience Engineering Research Group

This research is conducted to study the interdependencies within a multi-line railway network during disruption events. Disruptions will not only cause primary delay, which is directly linked to the disruption, but also trigger reactionary delays. The reactionary delay propagates throughout the network, posing a great challenge for the network oper...

Continuous advancements in GNSS systems have led, apart from the broadly used GPS, to the development of other satellite systems (Galileo, BeiDou, GLONASS), which have significantly increased the number of available satellites for GNSS positioning applications. However, despite GNSS satellites’ redundancy, a potential poor GNSS satellite signal (i....

Faults can have significant, negative impacts on the operation and performance of simple and complex dynamic systems. Based on the integration of Bayesian network diagnostic features with Petri net formalism, the existing Bayesian-supported Petri net tool has demonstrated the flexibility of using the Petri net approach for diagnosing failure scenar...

The maintenance strategy in railway transportation is crucial in ensuring safety, availability, and reducing operating costs. However, finding the optimal maintenance plan that takes into account the complex relationships between railway assets can be a challenging task. To address this challenge, this study introduces an Intelligent Petri Net (iPN...

Variations in clinical practice are common. However, some variations may cause undesired consequences. Careful consideration of their causes and effects is necessary to assure the quality of healthcare delivery. A modelling approach that could capture these aspects would help to achieve this goal. In this paper, a Newborn Life Support procedure is...

In this paper, defect detection and identification in aluminium joints is investigated based on guided wave monitoring. Guided wave testing is first performed on the selected damage feature from experiments, namely, the scattering coefficient, to prove the feasibility of damage identification. A Bayesian framework based on the selected damage featu...

There are 11,619 community pharmacies in England which dispense over 1 billion prescriptions each year, providing essential primary care to NHS (National Health Service) patients. These pharmacies are facing pressure from a number of sources including funding cuts and high demands on services, while trying to deliver the highest standards of care....

Optimal asset management strategies for wind turbine blades help to reduce their operation and maintenance costs, and ensure their reliability and safety. Structural health monitoring (SHM) can determine the health state of wind turbine blades through implementing damage identification strategies. The main load-bearing structure spar of the wind tu...

Landslide is one of the major geohazards threatening human life and economy. Landslides have claimed tens of thousands of lives in the new millennium worldwide and an estimated economic loss of $20 billion annually. Information on causes and impacts of landslide hazards can be found abundantly, however, studies on impacts of landslide on transport...

Bayesian Belief Network (BBN) methods can be adopted for reliability analysis and real-time monitoring of critical infrastructure. Conditional Probability Tables (CPTs) are used to describe the dependencies between nodes in the BBN. The CPTs are usually defined by using either expert knowledge elicitation process or data-driven learning methods, an...

The use of guided waves to identify damage has become a popular method due to its robustness and fast execution, as well as the advantage of being able to inspect large areas and detect minor structural defects. When a travelling wave on a plate interacts with a defect, it generates a scattered field that will depend on the defects geometry. By ana...

Large amounts of data are generated by structural health monitoring systems continuously. Data‐driven methods can transform the available data into valuable information for decision makers. However, these methods for structural health monitoring of bridges are usually developed and tested by analysing a finite element model of the bridge, where the...

Bridges are one of the most important assets of transportation networks. A closure of a bridge can increase the vulnerability of the geographic area served by such networks, as it reduces the number of available routes. Condition monitoring and deterioration detection methods can be used to monitor the health state of a bridge and enable detection...

This paper shows how to simulate highway traffic flows using a network-level traffic flow model (NTFM) for both urban and motorway road networks. It highlights how road maintenance works can be modelled using a roadwork node in the network and how the modelling can be used to predict the effects of maintenance works on the level of service of the h...

The occurrence of unexpected events, such as infrastructure failures and natural disasters, are unavoidable in railway operation. Traffic controllers and train operators are thus required to manage the situation and provide the best possible services for passengers. This paper presents a recoverability analysis model that can be used to evaluate th...

As technology advances, modern systems are becoming increasingly complex, consisting of large numbers of components, and therefore large numbers of potential component failures. These component failures can result in reduced system performance, or even system failure. The system performance can be monitored using sensors, which can help to detect f...

It has been estimated that European customers visit community pharmacies to access essential primary healthcare around 46 million times every day. Studies of dispensing error rates in community pharmacies have reported error rates of between 0.08% and 3.3% per item dispensed. While severe cases of dispensing inaccuracies often garner a high level o...

Structural Health Monitoring (SHM) techniques are able to monitor the behaviour of critical infrastructure over time, by improving the safety and reliability of the asset. A large amount of data is generated by SHM methods continuously. Therefore, machine learning methods can be developed in order to transform the available data into valuable infor...

A large amount of data is generated by Structural Health Monitoring (SHM) systems and, as a consequence, processing and interpreting this data can be difficult and time consuming. Particularly, if work activities such as maintenance or modernization are carried out on a bridge or tunnel infrastructure, a robust data analysis is needed, in order to...

Component failures in complex systems, such as aircraft fuel systems, can have catastrophic effects on system performance. There are a large number of components in these systems, each with a number of different failure modes, some of which can cause system failure. In order to detect and diagnose these component failures, sensors that monitor syst...

Studies of error rates in community pharmacies have reported error rates of between 0.014% and 3.3% per item dispensed. This suggests up to 36 million items per year may contain errors in England. In addition, literature shows that patient satisfaction with services is directly related to waiting times. There is a need for a method to model pharmac...

This paper reports on recent contributions by the Marie Skłodowska-Curie Innovative Training Network titled TRUSS (Training in Reducing Uncertainty of Structural Safety) to the field of structural safety in rail and road bridges (http://trussitn.eu). In TRUSS, uncertainty in bridge safety is addressed via cost efficient structural performance monit...

Railway infrastructure providers, such as Network Rail, who owns and manages the British railway infrastructure, can improve the performance and reduce the life cycle cost of their assets through delivering effective asset management. Having the capability to use computer based models to predict the future performance and life cycle cost of an asse...

UK customers visited community pharmacies to receive NHS prescriptions 1.104 billion times in 2016. One study of dispensing errors found an error rate of 3.3%. Severe dispensing inaccuracies often receive a high level of media attention, however, lower level errors could also be causing significant inefficiencies in the delivery of primary healthca...

The UK railway network is subjected to an electrification process that aims to electrify most of the network by 2020. This upgrade will improve the capacity, reliability and efficiency of the transportation system by providing cleaner, quicker and more comfortable trains. During this process, railway infrastructures, such as tunnels, require to be...

Railway importance in the transportation industry is increasing continuously, due to the growing demand of both passenger travel and transportation of goods. However, more than 35% of the 300,000 railway bridges across Europe are over 100-years old, and their reliability directly impacts the reliability of the railway network. This increased demand...

In the modern world, systems are becoming increasingly complex, consisting of large numbers of components and their failures. In order to monitor system performance and to detect faults and diagnose failures, sensors can be used. However, using sensors can increase the cost and weight of the system. Therefore, sensors need to be selected based on t...

More than 35% of the European railway bridges are over 100 years old and the increasing traffic loads are pushing the railway infrastructure to its limits. Bridge condition-monitoring strategies can help the railway industry to improve safety, availability and reliability of the network. In this paper, a Bayesian Belief Network method for condition...

More than 350,000 railway bridges are present on the European railway network, making them a key infrastructure of the whole railway network. Railway bridges are continuously exposed to changing environmental threats, such as wind, floods and traffic load, which can affect safety and reliability of the bridge. Furthermore, a problem on a bridge can...

Bridges are one of the most critical structures of the railway system. External loads may affect the bridge health state, and consequently their safety, availability and reliability can be improved by monitoring their condition and planning maintenance accordingly. In this paper, a Bayesian Belief Network (BBN) fault detection methodology for a tru...

Background Healthcare aims to deliver good patient outcomes. For many clinical procedures there are multiple alternative task sequences that can be performed. These deviations can influence procedure reliability, efficiency of usage of hospital resources and risk to staff and patient safety. Venepuncture is one of the most common invasive procedure...

A simulation framework based on the Petri Net model is proposed in this paper used for performing quantitative risk prognosis through extending the Bow-Tie model. A Petri Net model is built to include features, specific to assets, such as the condition of the asset, the projected operational usage, inspection and maintenance policies and degradatio...

The Overhead Line Equipment (OLE) is a critical sub-system of the 25 kV AC overhead railway electrification system. If OLE asset management strategies can be evaluated using a whole lifecycle cost analysis that considers degradation processes and maintenance activities of the OLE components, the investment required to deliver the level of performan...

In the modern world, systems are becoming increasingly complex, consisting of large numbers of components and their failures. In order to monitor system performance and to detect faults and diagnose failures, sensors can be used. However, using sensors can increase the cost and weight of the system. Therefore, sensors need to be selected based on t...

More than 35% of the European railway bridges are over 100 years old and the increasing traffic loads are pushing the railway infrastructure to its limits. Bridge condition-monitoring strategies can help the railway industry to improve safety, availability and reliability of the network. In this paper, a Bayesian Belief Network method for condition...

A risk and reliability modelling framework for railway assets based on the Petri Net and the Bow-Tie models is proposed in this paper. A Petri Net model together with the Monte Carlo simulation is used to replicate the projected operational usage of the asset, inspection and maintenance policies and degra-dation of the asset and to estimate the fut...

A three-phase separator (TPS) is one of the key components of offshore oil processing facili-ties. Oil is separated from gas, water and solid impurities by the TPS before it can be further processed. Fail-ures of the TPS can lead to unplanned shutdowns and reduction of the efficiency of the whole oil processing facility as well as posing hazards to...

The overhead line equipment (OLE) is a critical sub-system of the 25kV AC overhead railway electrification system. There is a need to evaluate OLE asset management strategies through a whole life cost analysis that considers degradation processes and maintenance activities of the OLE components so that the investment required to deliver the level o...

A high demand of oil products on daily basis requires oil processing plants to work with maximum efficiency. Oil, water and gas separation in a three-phase separator is one of the first operations that are performed after crude oil is extracted from an oil well. Failure of the components of the separator introduces the potential hazard of flammable...

This paper presents a road maintenance planning model that can be used to balance out maintenance cost and road user cost, since performing road maintenance at night can be convenient for road users but costly for highway agency. Based on the platform of the network traffic flow modelling, the traffic through the worksite and its adjacent road link...

Healthcare aims to deliver good patient outcomes. However deviations in the application of medical procedures can result in failure to deliver reliable care, variation in patient results, waste of hospital resources and increase of risk to staff and patients. Venepuncture – the act of taking blood samples for laboratory tests – has been practised f...

The study shows how the evolution of two-way traffic flows on a local highway network can be predicted over time using a network-level traffic flow model (NTFM) to model both urban and motorway road networks. After a brief review of the main principles of the NTFM and its associated sub-models, the paper describes how a maintenance worksite can be...

This paper presents a new pavement management system (PMS) to achieve the optimal pavement maintenance and rehabilitation (M&R) strategy for a highway network using genetic algorithms (GAs). Optimal M&R strategy is a set of pavement activities that both minimise the maintenance cost of a highway network and maximise the pavement condition of the ro...

Failures of railway point systems (RPSs) often lead to service delays or hazardous situations. A condition monitoring system can be used by railway infrastructure operators to detect the early signs of the deteriorated condition of RPSs and thereby prevent failures. This paper presents a methodology for early detection of the changes in the measure...

The railway transport system is experiencing an increasing level of traffic demand in terms of both passengers and freight. The 24/7 railway has been stated as a possible solution to satisfy the future growth in demand. However a greater utilisation of the network will accelerate deterioration processes and reduce the time slots for maintenance. In...

Context Worldwide evidence has shown that failure to deliver reliable healthcare results in variations in patient outcomes, waste of resources and even harm to patients. For example, in venepuncture, a simple common invasive clinical procedure, preventing errors is paramount to assure not only the quality of the blood sample but also to prevent har...

The research reported in this paper develops a network-level traffic flow model (NTFM) that is applicable for both motorways and urban roads. It forecasts the traffic flow rates, queue propagation at the junctions and travel delays through the network. NTFM uses sub-models associated with all road and junction types that comprise the highway. The f...

Health management systems are now standard aspects of complex systems. They monitor the behaviour of components and sub‐systems and in the event of unexpected system behaviour diagnose faults that have occurred. Although this process should reduce system downtime, it is known that health management systems can generate false faults that do not repr...

In this paper a novel road network flow model is presented, suitable for modelling both motor-way and urban roads. A road network is modelled using a directed graph, consisting of typical roads and junctions, with different traffic flow inputs throughout the day. The model is based on a simple idea of balancing out the traffic flow in the network,...

Fault diagnostics systems are incorporated to determine the health of the system they monitor. There are however times when the diagnostics system reports faults which do not exist. This situation commonly arises at system start-up when high vibration levels exist and the systems are not performing in the same way as when they are operational. Unne...

A fault propagation modeling technique using Petri nets is outlined in this paper, when a system performs a phased mission with a different success criterion in each phase. Component failure effects are obtained by monitoring the deviations in the system process variables, when single or multiple failures are introduced. The system behavior is mode...

Autonomous systems are becoming more commonly used, especially in hazardous situations. Such systems are expected to make their own decisions about future actions when some capabilities degrade due to failures of their subsystems. Such decisions are made without human input, therefore they need to be well-informed in a short time when the situation...

A phased mission analysis approach for cooperating platforms is outlined in this paper, when a common mission goal is achieved through collaboration of a number of individual platforms. Phase failure probabilities for individual platform mission and the overall mission are used to measure the mission success. Since any platform capability can degra...

The use of autonomous systems is becoming increasingly common in many fields. A significant example of this is the ambition to deploy UAVs (unmanned aerial vehicles) for both civil and military applications. In order for autonomous systems such as these to operate effectively they must be capable of making decisions regarding the appropriate future...

Fault tree analysis is commonly used to assess the reliability of potentially hazardous industrial systems. The type of logic is usually restricted to AND and OR gates which makes the fault tree structure coherent. In non-coherent structures not only components’ failures but also components’ working states contribute to the failure of the system. T...

Fault Tree Analysis (FTA) is widely applied to assess the failure probability of industrial systems. Many computer packages are available which are based on conventional Kinetic Tree Theory methods. When dealing with large (possibly non-coherent) fault trees, the limitations of the technique in terms of accuracy of the solutions and the efficiency...

This article was published in the journal, Proceedings of the Institution of Mechanical Engineers, Part O: Journal of Risk and Reliability [© IMechE] and is also available at: http://journals.pepublishing.com/content/119859 Risk and safety assessments performed on potentially hazardous industrial systems commonly utilize fault tree analysis (FTA) t...

This paper presents a decision making strategy for autonomous multi-platform systems, wherein a number of platforms perform phased missions in order to achieve an overall mission objective. Phased missions are defined for both single and multi-platform systems and a decision making strategy is outlined for such systems. The requirements for a tool...

This article is Restricted Access. It was published in the journal, International Journal of Reliability and Safety [© Inderscience] and is available at: www.inderscience.com/ijrs/ This paper presents an extended strategy for the analysis of complex fault trees. The method uses simplification rules, which are applied to the fault tree to reduce it...

This conference paper is Restricted Access. More information can be found at http://www.mmr2007.org/index.php?id=1 Fault Tree Analysis (FTA) to forecast the probability of system failure. The type of logic for the top event is usually limited to AND and OR gates which leads to a coherent fault tree structure. In noncoherent fault trees components’...

Fault tree analysis is commonly used in the reliability assessment of industrial systems. When complex systems are studied conventional methods can become computationally intensive and require the use of approximations. This leads to inaccuracies in evaluating system reliability. To overcome such disadvantages, the binary decision diagram (BDD) met...

Fault tree analysis (FTA) is commonly used when conducting risk assessments of industrial systems. A number of computer packages based on conventional analysis methods are available to perform the analysis. However, dealing with large (possibly non-coherent) fault trees can expose the limitations of the technique in terms of accuracy of the solutio...

This is a conference paper. It was presented at 23rd International System Safety Conference, August 22-26, 2005, San Diego, Westin Hotel. Fault Tree Analysis is a commonly used technique to predict the causes of a specific system failure mode and to then determine the likelihood of this event. Over recent years the Binary Decision Diagram (BDD) met...

This is a conference paper. ©2006 IEEE. Personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution to servers or lists, or to reuse any copyrighted component of this work in other works must be obtained f...