Event Of Failure Research Articles

SRFACS: A secure and robust framework for anonymous communication systems.

Anonymous communication is crucial for preserving user privacy in various applications, such as anonymous browsing, secure online payments, and electronic voting. However, current systems face significant challenges related to robustness, fault tolerance, and efficient communication management. This paper introduces SRFACS (Secure and Robust Framework for Anonymous Communication Systems), designed to address these issues by integrating advanced cryptographic techniques with a structured communication framework. Traditional anonymous communication systems usually lack sufficient fault tolerance, making them vulnerable to node failures, especially in asynchronous environments. In order to overcome these limitations and ensure that the system can keep running in the event of node failure (especially in an asynchronous environment), SRFACS integrates an improved asynchronous Byzantine Fault Tolerant (ABFT) protocol. We use this protocol to expand the traditional single communication node into a structured node group, and handle up to (n - 1)/3 faulty nodes in these groups, so as to enhance fault tolerance and maintain continuous operation. To efficiently manage inter-group communication, SRFACS utilizes leader nodes to coordinate and streamline the communication processes. To mitigate the risks associated with leader failures, we have implemented an efficient leader change protocol that promptly replaces defective leaders, ensuring uninterrupted system performance. Additionally, to prevent erroneous leader actions from compromising the system, we have introduced an advanced multi-signature scheme. This approach secures communication by requiring multiple signatures for verification processes. Furthermore, we have implemented a reputation incentive mechanism to encourage nodes to maintain optimal performance and avoid malicious behavior. This mechanism evaluates nodes according to their past activities and reliability to achieve dynamic updates of SRFACS node groups. We have conducted rigorous security analyses and component performance evaluations of SRFACS, further confirming its potential as a promising secure communication solution.

Regional bridge risk assessment due to the combined effect of flooding and overloading events in Manitoba

The challenges experienced by Canada’s aging infrastructure require probabilistic methods to address the threats that bridge systems are exposed to. This study provides a framework to evaluate risk associated with two major bridge hazards such as flooding and overloading in Manitoba. The probability of failure of highway bridges due to overloading is assessed as a function of traffic volume and overweight percentages. The probability of failure due to flooding is obtained from a spatial analysis of the water levels. Finally, consequences of failure are established from the analysis of insurance exposure, including climate change effects. Historic data are projected ten years into the future through an ARIMA model. The results of the analysis show that the risk for bridges in the south-west regions of Manitoba is expected to increase by 2035 up to 40% for water levels of 3.0 m and up to 0.6% for a threshold of 12.0 m.

Integrity of Surface and Sub-Surface Pipeline for Transmission of Crude Oil By-Products: Recent Developments and Future Perspectives

Pipelines play a crucial role in transporting large volumes of gas and oil over long distances due to their safety, efficiency, and cost-effectiveness. Maintaining the integrity of both surface and subsurface pipelines is vital for reliable operations and preventing costly failures that could result in environmental contamination from oil or gas spills. Pipeline degradation often results from electrochemical processes over time, affecting the surface in contact with the environment. This study reviews a decade of literature on methodologies, contributions, and drawbacks related to surface and subsurface pipeline integrity. It provides an overview of progress in PSE-aided thermal cracking production and introduces frameworks, methods, and algorithms proposed in the past 10 years, discussing their advantages, limitations, and industrial applications. Additionally, the paper identifies research gaps, particularly in the accuracy and validation of current methodologies. The study concludes by proposing future recommendations aimed at enhancing environmental sustainability, stressing the potentially catastrophic consequences of pipeline failures. It serves as a resource for experts in non-destructive testing and those interested in the field.

An aperiodically intermittent control for finite-time and fixed-time synchronization of stochastic FCNN with switching parameters

The main objective of this paper is to design an aperiodically intermittent control to ensure the finite and fixed time synchronization of fuzzy cellular neural networks (FCNNs) involving switching parameters with threshold properties, time-dependent discrete, continuous-type delays, and stochastic disturbances during transmission. Cellular neural networks (CNNs), with their grid-like structure, excel in image-processing tasks. Incorporating the fuzziness in the CNNs may handle the uncertainties and incomplete information in an effective manner. Furthermore, this paper introduces the concept of user-controlled FCNNs, which retain the dynamic properties of conventional FCNNs while incorporating significant factors that could potentially degrade the performance of the considered model. Due to randomness, FCNNs are framed as a set of stochastic differential equations with memristors. Generally, a memristor functions as a non-volatile memory device, reserving past data and utilizing it in the event of transmission failure. Further, the synchronization process is an effective approach that helps to ensure the dynamical behaviors of two different models; hence, the paper formulates the synchronization problem for the FCNN model with control (response) and without control input (drive). In terms of control design, this paper also considers the aperiodically intermittent control (APIC) scheme that can drive the user-controlled FCNN solution trajectories onto conventional FCNN solution trajectories within a prescribed time. Additionally, the APIC scheme incorporates an adaptive mechanism that effectively manages switching behaviors and uncertainties. Furthermore, this study proposes a theoretical framework in the form of sufficient stability conditions that helps to ensure the synchronization of the drive-response model via the global asymptotical stability of the stochastic error model derived from the drive-response model under the APIC scheme in the mean square. The proposed stochastic FCNN model is numerically simulated, and the corresponding outcomes are graphically illustrated.

Resilient Multi-Robot Coverage Path Redistribution Using Boustrophedon Decomposition for Environmental Monitoring

This study introduces a resilient and adaptive multi-robot coverage path planning approach based on the Boustrophedon Cell Decomposition algorithm, designed to dynamically redistribute coverage tasks in the event of robot failures. The proposed method ensures minimal disruption and maintains a balanced workload across operational robots through a propagation-based redistribution strategy. By iteratively reallocating the failed robot’s coverage path to neighboring robots, the method prevents any single robot from becoming overburdened, ensuring efficient task distribution and continuous environmental monitoring. Simulations conducted in five distinct environments, ranging from simple open areas to complex, obstacle-rich terrains, demonstrate the method’s robustness and adaptability. A key strength of the proposed approach is its fast and efficient task reallocation process, achieved with minimal propagation cycles, making it suitable for real-time applications even in complex scenarios. The approach reduces task variance and maintains balanced coverage throughout the mission.

IoT Integration of Failsafe Smart Building Management System

This research investigates the energy consumption of buildings managed by traditional Building Management Systems (BMSs) and proposes the integration of Internet of Things (IoT) technology to enhance energy efficiency. Conventional BMSs often suffer from significant energy wastage and safety hazards due to sensor failures or malfunctions. These issues arise when building systems continue to operate under unknown conditions while the BMS is offline, leading to increased energy consumption and operational risks. The study demonstrates that integrating IoT systems with existing BMSs can substantially improve energy efficiency in smart buildings. The research involved designing a system architecture prototype, performing MATLAB simulations, and a real-life case study which revealed that IoT devices are effective in reducing energy waste, particularly in Heating, Ventilation, and Air Conditioning (HVAC) systems and lighting. Additionally, an auxiliary bypass system was incorporated in parallel with the IoT system to enhance reliability in the event of IoT system failures. Preliminary findings indicate that the integration of IoT systems with traditional BMSs significantly boosts energy efficiency and safety in smart buildings. Simulation results reveal an hourly average power savings of 36.8 kw with the integrated failsafe model for all scenarios. This integration offers a promising solution for advancing energy management practices and policies, thereby improving both operational performance and sustainability in building management.

Virtual Generator to Replace Backup Diesel GenSets Using Backstepping Controlled NPC Multilevel Converter in Islanded Microgrids with Renewable Energy Sources

This work presents an islanded microgrid energy system that uses backstepping control applied to neutral point clamped (NPC) multilevel converters coupled with batteries to behave as virtual generators, able to absorb surplus renewable energy, therefore increasing the penetration of renewable energy sources. Additionally, on a charged battery the virtual generator allows turning-off the backup diesel generator set (GenSet). Aside from improving energy efficiency, the battery-connected multilevel converter aims to regulate frequency, improves power quality, and keeps the microgrid operational in the event of a GenSet failure. The backstepping controlled NPC multilevel converter emulates a virtual generator injecting power to perform as the primary and secondary microgrid frequency controller. Additionally, AC voltage control is implemented, which enables running the islanded microgrid only with multilevel converters, supplied by the battery while integrating solar and wind energy sources. Energy demand and renewable energy forecasts are used to manage the battery state-of-charge. Simulation results, obtained from switched and phasor models show that energy storage and the backstepping frequency control enables the compensation of power fluctuations from renewable energy sources. Furthermore, in the event of the main GenSet failure, the controlled virtual generator keeps the microgrid running for a few minutes, until another GenSet is ready to supply the microgrid. Therefore, the microgrid integration of the battery-connected multilevel converter results in a significant boost in energy efficiency by allowing the disconnection of the backup GenSet.

Identifying risk factors for wheelchair damage, part failure, and adverse consequences to the user

No tools or technologies exist to inform data-driven inspection schedules for wheelchairs. To develop such a schedule, this study identifies risk factors linked with manual wheelchair damage, part failures, and consequences and evaluates preferences for a new wheelchair servicing technology. A mixed methods study was performed with manual wheelchair users at The Ohio State University Martha Morehouse Clinic. Demographic data, wheelchair information, failure counts, and consequences suffered by the user were collected using surveys. Wheelchair usage was collected for a month using a sensor. A servicing smartphone app that connects with the sensor was demonstrated as a new servicing technology, and participant preferences were recorded. Thirty participants completed the survey testing procedures. Twenty-three collected usage data and eighteen collected it for over a week. At least 215 wheelchair part failures with an average of 13.4 ± 14.8 self-reported part failures and 4.7 ± 4.8 high-risk failures occurred in 12 months before the first study visit. Two weeks of collected data from 18 participants showed that normalised road shocks, age, and weight were associated with the condition of wheels and frames, as well as self-reported caster failures. Participants responded with a favourable preference for the new wheelchair servicing technology, with more than half of them interested in buying and using it. Risk factors like road shocks and user’s age and weight are associated with part damage towards failures and self-reported failures that risk injury. These factors can be modelled to develop and test the efficacy of wheelchair inspection schedules.

Designing for climate change: twenty-five design features to improve sanitation technology resilience in low- and middle- income countries

Climate change is exacerbating events such as floods and droughts, and trends including sea-level rise, leading to failures in sanitation technologies, increased public health risks and environmental pollution. To reduce these risks, it is crucial to incorporate climate resilience into sanitation technology designs. In this study, we reviewed academic and selected grey literature and identified 25 design features that can contribute to the technology’s resilience to an increasingly volatile and extreme climate. Design features that were conceptually similar were collated into seven categories. These categories included: (i) avoid exposure to hazards, (ii) withstand exposure to hazards, (iii) enable flexibility, (iv) contain failures, (v) limit consequences of complete failure, (vi) facilitate fast recovery and (vii) features that provide resilience benefits beyond technological resilience. In this paper we define the categories and design features, and provide examples of each feature in practice. We also outline how the resilience design features can support sanitation designers and implementers to critique the climate resilience of sanitation technology, and prompt more resilient designs of sanitation technology.

Consequence of high-pressure CO2 pipeline failure: Full-scale burst test and numerical simulation

Carbon Capture and Storage (CCS) is a widely acknowledged technique for mitigating global warming. High-pressure pipelines emerge as the most efficient and economical means to transport Carbon Dioxide (CO2) from source to storage sites. Given the hazardous nature of CO2 and the potential for catastrophic consequences in an unplanned release, ensuring safe operation of CO2 pipelines is paramount. This necessitates a comprehensive understanding of the potential consequences of CO2 pipeline failures. This paper presents experimental measurements of CO2 dispersion profiles following a full-scale burst test, simulating a real-world CO2 pipeline failure scenario. The experimental setup comprised an 82.7 m buried pipeline test section with a diameter of 324 mm, connected at both ends to 60 m reservoirs. The rupture of the pipeline was initiated at the middle of the test section using an explosive charge. Measurements were carried out for the transient downwind CO2 concentrations and temperatures following the explosive release. Computational Fluid Dynamics (CFD) models employing proposed numerical methods were used to simulate the experimental scenario. The performance of these methods was validated through comparisons with experimental measurements. The validated numerical methods were then employed to predict consequence distances for full-scale CO2 pipeline failures in real-world scenarios.

Predicting the probability of failure in medicinesʼ public procurement

The quality and timeliness of medicinesʼ supply to the healthcare system through public procurement is an urgent task of public policy in all countries of the world, including Russia. Failure to close (failure of tenders, termination of already concluded contracts) procurement procedures in such a socially significant area carries risks for the population, provokes the emergence of hidden transaction costs for the budget system to eliminate the consequences of procurement failures. In their previous works, the authors identified the factors that lead to the failure to close tenders for the purchase of remedies, and initially assessed the consequences of their influence on procurement procedures. The purpose of this article is to present a mathematical model of the probability of non-closure tenders based on the obtained results. To achieve this goal, through processing more than 1 million notifications of public procurement of remedies for 2022–2023, collected from the open sources, the tasks with no methodological solutions were completed. Thus, a set of features accompanying the failure to close procedures for the purchase of remedies was compiled. The composition of identified features was analyzed; their influence on non-closure of the procedure was assessed. A model of the probability of non-closure of the procedure was constructed, and the results were interpreted. Unlike previously published studies, the forecast model was implemented on the ensembles of decision trees using gradient boosting. This made possible to significantly improve the quality of the forecast for each factor affecting the probability of non-closure of the bidding. The results obtained in the article are not only scientifically novel, but can also be used by regulatory and control bodies in public procurement to develop methodological recommendations for customers on establishing optimal conditions for concluding and fulfilling contracts, which will reduce procurement risks and damage to the state budget.

Fault-tolerant partition resolvability of cycle with chord.

In the realm of connected networks, distance-based parameters, particularly the partition dimension of graphs, have extensive applications across various fields, including chemistry and computer science. A notable variant of the partition dimension is the fault-tolerant resolving partition, which is critical in computer science for networking, optimization, and navigation tasks. In networking, fault-tolerant partitioning ensures robust communication pathways even in the event of network failures or disruptions. In optimization, it aids in developing efficient algorithms capable of withstanding errors or changes in input data. In navigation systems, fault-tolerant partitioning supports reliable route planning and navigation services under uncertain or dynamic conditions. This paper focuses on the fault-tolerant partition dimension within the specific context of the cycle with chord graphs, exploring its properties and implications for enhancing the robustness and reliability of networked systems.

Agrobiodiversity and food security: challenges and sustainable solutions

Objective: Agricultural biodiversity, also known as agrobiodiversity, encompasses the variety of plants, animals, and microorganisms that are directly or indirectly involved in agriculture. This diversity is the result of millennia of selection, management, and domestication of species, which has allowed societies to adapt to different environmental and cultural conditions. However, in recent decades, the loss of agrobiodiversity, accelerated by industrial agriculture, the expansion of monocultures, and the reduction of varieties, has put global food security at risk. This diversity is crucial to ensuring the resilience of agricultural systems in the face of challenges such as climate change, emerging pests, and the depletion of natural resources. This paper examines the importance of conserving agricultural biodiversity from the perspective of food security. It emphasizes how agrobiodiversity not only contributes to the stability of food production but also improves human diets by diversifying crops and providing essential micronutrients. Design/Methodology/Approach: A search was conducted on the following scientific information platforms: Web of Science database and Google Scholar. A systematic search for publications related to agrobiodiversity systems was carried out in the WoS database and Google Scholar over the last 49 years (1975–2024). Results: Genetic erosion is particularly concerning because genetic diversity is essential for crops to face environmental challenges such as climate change, pests, and diseases. The loss of traditional varieties, which are selected by local farmers to adapt to specific conditions, increases agriculture's vulnerability to external disruptions. These landraces, having been cultivated in genetically diverse mosaics, offer protection against catastrophic losses in the event of crop failures due to extreme conditions or diseases. Findings/Conclusions: Genetic diversity allows for the development of sustainable solutions to pests and diseases, reducing dependence on pesticides and promoting more environmentally friendly farming practices. However, challenges related to biodiversity conservation persist, making it essential to implement public policies that promote agrobiodiversity and address the socioeconomic issues that limit its adoption.

IoT-Based Control, Monitoring, and Protection System for 3-Phase Induction Motors in Electric Motorcycles

This study investigates the application of the Internet of Things (IoT) for wireless control and monitoring of a 3-phase electric motor using a smartphone. The system integrates PZEM-004T, DS18B20, and Hall Effect sensors to collect data on voltage, current, temperature, and rotational speed using the NodeMCU ESP8266 microcontroller. Measurements are displayed on an LCD and transmitted to the Blynk server for smartphone access. A comparative method evaluates the accuracy of sensor readings against standard measuring instruments. Results obtained an average percentage error of 0.5% for the R phase voltage, 0.2% for the S phase, and 0.1% for the T phase. Current measurements reveal errors of 5% for the R phase, 10.3% for the S phase, and 11.7% for the T phase. The control system’s performance varies with internet speed, with an average delay of 0.99 seconds on a 4G network and 2.51 seconds on 3G. Additionally, the study evaluates three protection mechanisms, demonstrating that the motor stops within 4.03 seconds in the event of a phase failure, while overcurrent and overheating protections activate within 8.47 seconds and 3.64 seconds, respectively. Overall, the findings affirm the viability of IoT in motor monitoring and control, emphasizing accuracy and response times under varying conditions.

Intelligent control algorithms to ensure the flight safety of aerospace vehicles

An overview of the architectures, functions and algorithms of aircraft-type aerospace vehicles equipped with fly-by-wire (FBW) digital integrated control systems (ICS) is given. The ICS has a hierarchical architecture, including the primary, backup and emergency control systems with a sophisticated control reconfiguration logic in the event of failures. Digital control computers have dissimilar redundancy of equipment and software. At the atmospheric flight stage, integrator control laws provide the specified control characteristics, flight envelope protection, automatic trim of vehicle and crew workload alleviation. Further integration of manual and automatic control, implementation of the control philosophy as a continuation of the pilot's actions, more intellectual control system and human-machine interface, use of multiple control surfaces to ensure optimal vehicle configuration and alleviate structural loading together with basic control functions are considered as promising areas for ICS improvement.

Performance and Robustness of Physiological Controllers With Integrated Pressure Sensors on Inflow Cannula.

The control of left ventricular assist devices (LVADs) requires sensors and/or estimators to account for the physiological state of the patient and apply advanced controllers. Sensor characteristics are a challenge when using implantable pressure sensors because they influence the quality of physiological control and the robustness of the controlled system. The objective of this work is to investigate the performance and robustness of LVAD controllers that operate based on LVAD integrated pressure sensors. Four pressure-based LVAD controllers are tested with a HeartMate 3 that has an integrated pressure sensor. Controller sensitivity as well as robustness to sensor drift and noise are evaluated based on controller response to large changes in preload and afterload. A fail-safe strategy for sensor failure used also to investigate the reliable operation of the LVAD in realistic conditions. All tested controllers are sensitive to drifting pressure signals, which can lead to unstable behavior. The results show that two controllers are robust to noise. The other two controllers show high deviation and oscillation in cardiac output even for small noise. Additionally, a noticeable difference of the controller's response between simulated and measured pressure input was observed, indicating the need for a robust controller design. Reliable operation even in the event of a sensor failure was achieved on the basis of a fail-safe control system.

Non-singular sliding mode control-based attitude control analysis of ELITE satellite with flywheel failures

Abstract This paper addresses the challenge of maintaining the attitude control of the ELITE satellite in the event of flywheel failures. Given the critical need for highly stable and precise attitude control during Time-Delay Integration (TDI) Imaging missions, a failure in any flywheels poses a significant threat to the satellite’s attitude control stability and accuracy. To tackle this issue, a Non-singular Sliding Mode Control (NSMC) method was proposed to ensure ELITE’s continued performance under flywheel failure conditions. The research involves a thorough analysis of ELITE’s attitude dynamics, followed by designing an NSMC tailored to its specifications. Theoretical validation of the NSMC’s finite-time stability was achieved using the Lyapunov function. Numerical simulations conducted demonstrate that the proposed NSMC method enables ELITE to maintain its attitude control stability and precision even in the presence of flywheel failures, thereby ensuring mission continuity and reliability.

Permeation of per- and polyfluoroalkyl substances (PFAS)-laden leachate in landfills as an outcome of puncture failures of high-density polyethylene geomembranes

In response to growing environmental concerns regarding the presence of per- and polyfluoroalkyl substances (PFAS) in landfills, this study explores PFAS permeation through pinhole defects of high-density polyethylene (HDPE) geomembranes (GMs) experimentally. Specifically, this study aims to: (i) investigate the adsorption of PFAS onto HDPE GMs, (ii) evaluate the effectiveness of GMs experimentally in retaining PFAS-laden leachate in the event of a puncture failure, (iii) assess the critical conditions leading to puncture failure of GM using mechanical characterization testing with complementary finite element method (FEM) analyses with the input data from mechanical characterization. Our findings show limited intermolecular attractive interactions between PFAS and GMs, and surfactant properties of PFAS contribute to higher leachate permeation through pinholes. In general, highly fluorinated, short chain PFAS exhibit increased permeation rates, which was attributed to their size and greater propensity to align at the water-air interface. This study underlines the environmental implications of PFAS-laden leachates especially when there are no proper liner systems or leachate collection systems in place underscoring the necessity for modern landfill design and management practices to mitigate environmental risks associated with PFAS.

Metabolic Consequences of Advanced Chronic Heart Failure and its Modification by Implantation of a Durable Left Ventricular Assist Device.

Heart failure (HF) is a clinical syndrome characterized by the inability of the heart to provide adequate perfusion to tissues and organs, resulting in typical symptoms such as fatigue, dyspnea, dyspepsia, or swelling due to decreased cardiac output. With its increasing prevalence, heart failure has become one of the leading causes of morbidity and mortality worldwide, imposing a significant burden on the population by reducing long-term life expectancy and raising hospital costs. Indeed, over 20 million people worldwide suffer from heart failure, with a 5-year mortality rate of 60-70%. As heart failure progresses, various structural and metabolic changes occur within the myocardium and organ systems. In the past two decades, therapeutic options for heart failure patients have significantly expanded. In addition to novel pharmacological treatment, advanced surgical methods such as heart transplantation (HTx) and the implantation of durable left ventricular assist devices (LVADs) are available for patients with end-stage heart failure. This review discusses the pathophysiological aspects and metabolic consequences of heart failure and metabolic changes, as well as the benefits and challenges of implanting a left ventricular assist device. Furthermore, future targets for heart failure diagnostics and therapy will be highlighted.

A Study on Ways to Expand the Speed Operation Range of Dental Laboratory Handpiece Motors Using Low-Cost Hall Sensors

In the dental prosthetics field, BLDC micro-motors are primarily used for implant procedures. As dental materials become increasingly harder, there is a growing demand for higher performance motors to precisely process these materials. However, difficulties in motor development arise due to price competitiveness. Dental motors require capabilities such as low-speed, high-torque for drilling operations and high-speed rotation for precise machining of high-strength dental materials. Additionally, there is a requirement to address thermal issues to prevent user burns due to motor-generated heat. Typically, motors requiring precision control utilize high-resolution position sensors like encoders or resolvers to acquire and control the rotor’s position. However, the high cost of these sensors and constraints such as increased device size pose challenges in maintaining price competitiveness. In this paper, we propose a control algorithm that satisfies the requirements for low-speed, high-torque and high-speed operation requirements for precision machining without hardware modifications using a BLDC micro-motor equipped with an inexpensive Hall sensor commonly used in the dental field. Furthermore, the algorithm is designed to ensure stable operation even in the event of Hall sensor failure or malfunction, and its effectiveness is validated through experiments.