Backup System Research Articles

Impact of after-hours surgery on outcomes of acute type A aortic dissection repair.

To establish whether emergency surgery performed outside working hours (after hours) contributed to adverse outcomes for patients with acute type A aortic dissection (ATAAD). We reviewed the operation records of ATAAD repair in our institution from 2004 to 2019 (n = 187). Emergency surgery was performed by one of a few teams of experienced surgeons, regardless of the time of day. Patients were divided into two groups based on the surgery start time: during working hours (n = 65) and after hours (n = 122). A propensity score-matched analysis was performed for 58 pairs of patients. The overall in-hospital mortality was 6.9% for the working-hours group and 13.8% for the after-hours group. There were no significant differences between the groups in the relatively limited study population (n = 187). Surgeon experience and aortic interventions did not differ remarkably between the groups. After-hours repair was not associated with postoperative complications. There were no significant differences in the long-term survival or aortic event-free rates between the groups. After-hours surgery did not affect the short- or long-term outcomes of ATAAD repair under our backup system, which supports the recommendation of immediate surgical repair. Efforts to minimize the discrepancies between working hours and after hours could help to improve the surgical outcomes of patients undergoing ATAAD repair.

The Failure Protection of Wireless-Based IIoT Technology for Fluid Level Control Systems

A novel protection mechanism was proposed for failure of a wireless-based IIoT system to control water level. Control via wireless communication can be executed safely using designed protection. A secondary path as a mesh network was automatically enabled to occur if the main MQTT network protocol failed. System backups were no longer required, with increased reliability of the wireless control network and low risk of failure. Performance control via the developed IIoT was demonstrated. Ability of the protection system to combat network failure was confirmed experimentally.

Comparative transient simulation of a renewable energy system with hydrogen and battery energy storage for residential applications

Energy systems for the building sector nowadays are moving towards using renewable energy sources such as solar and wind power. However, it is nearly impossible to fully develop a multi-generation energy system for a building only relying on these sources without convenient energy storage, backup systems, or connection to the grid. In this work, using TRNSYS software, a model was developed to study the transient behavior of an energy system applicable for residential buildings to supply the heating, cooling, domestic hot water, and electricity in demand. This study contains the comparison of two methods of energy storage, a hydrogen fuel cell/electrolyzer package and a conventional battery system. This study also provides information on environmental impacts and economical aspects of the proposed system. The results show that for an HVAC system when using hydrogen storage system the capital cost is twice the cost of using a battery system. However, the hydrogen system shows better performance when used at higher loads. Hydrogen storage systems show higher performance when used at higher size units.

Optimal sizing of a hybrid PV-WT-battery storage system: Effects of split-ST and combined ST + ORC back-ups in circuit charging and load following

This study explores the opportunities in deploying split Stirling and combined Stirling and organic Rankine cycle (ORC) in circuit charging and load following dispatch modes, respectively as the back-up of a hybrid renewable energy system. The optimal number of system components in each dispatch mode that simultaneously minimises the loss of power supply probability (LPSP), levelised cost of energy (LCOE) and dumped power have been found by implementing an evolutionary algorithm-based multi-objective optimisation approach. Then, a multi-criteria decision making tool is deployed to select the best configuration from the Pareto set. The optimal hybrid system configuration obtained have been compared to the traditional diesel generator back-up system base case, to demonstrate performance improvements with the deployment of the proposed back-ups. The results show deploying Stirling + ORC back-up in load following leads to 60.70% and 33.71% reductions in the LCOE and CO2 emissions, respectively compared to the base case but with slightly higher LPSP. While 61.4%, 33% and 24.47% reductions in the LCOE, CO2 emissions and LPSP have been observed with the deployment of split Stirling in circuit charging mode. Further results from the dynamic simulation highlight the energy cost, reliability, dumped power and battery performance of the optimal system respond to seasonal changes in the test location. Other observed results show the change in the market price and number of the photo-voltaic generator that generates 50% of the total power, strongly affect the performance of the optimal system. The proposed biomass powered Stirling based back-ups are promising alternatives to replace the traditional diesel generator back-ups in improving the green energy system’s reliability.

Understanding redundancy and resilience: Redundancy in life is provided by distributing functions across networks rather than back-up systems: Redundancy in life is provided by distributing functions across networks rather than back-up systems.

Understanding how evolution generates and maintains redundancy to cope with damage and loss of function in living systems could inspire applications from new therapies to resilient computer networks.

Using a computer based selection model for sizing of solar panels and battery back-up systems for use in a floating in-pond raceway

The In-pond Raceway (IPR) is a relatively new option for production aquaculture, which depends on water moving devices to provide constant flow. Failure of these devices will often result in a catastrophic loss of fish in the system. Thus, robust power backup systems are necessary to mitigate risk in the event of prolonged power outage. Because these systems must be dependable and many suitable locations for these raceways are in ponds in remote locations, farmers have considered utilizing off-grid solar photovoltaic (PV) systems with battery storage. PV with battery storage eliminates the expense of running utility power to remote areas and eliminates the associated risk of power failure when these lines go down. However, the PV and battery storage must be properly sized to ensure continuously available power. This study modeled energy requirements using a daily energy balance for these unique systems. The model was then utilized to determine whether sized systems could withstand varying electric loads based on monitored hourly climatological conditions at seven different locations within the state of Kentucky in the United States. Determining the appropriate size was an iterative process, where the battery storage and PV array were incrementally increased until the model predicted that the system would provide continuous power year-round. The model was also used to examine the effects of undersized systems. Energy depletion events (when not enough energy remained to drive the water moving device) were clustered in groups of multiple days in winter months over the twenty-two-year dataset. Therefore, undersized systems may be appropriate if there was no intention of stocking fish in winter. Establishing this model led to the development of a design decision support tool aimed at potential new Aquaculture producers and a series of recommendation tables, with the intention of streamlining the initial design process for this novel technology.

Optimal Power Sharing in Microgrids Using the Artificial Bee Colony Algorithm

In smart grids, a hybrid renewable energy system that combines multiple renewable energy sources (RESs) with storage and backup systems can provide the most cost-effective and stable energy supply. However, one of the most pressing issues addressed by recent research is how best to design the components of hybrid renewable energy systems to meet all load requirements at the lowest possible cost and with the best level of reliability. Due to the difficulty of optimizing hybrid renewable energy systems, it is critical to find an efficient optimization method that provides a reliable solution. Therefore, in this study, power transmission between microgrids is optimized to minimize the cost for the overall system and for each microgrid. For this purpose, artificial bee colony (ABC) is used as an optimization algorithm that aims to minimize the cost and power transmission from outside the microgrid. The ABC algorithm outperforms other population-based algorithms, with the added advantage of requiring fewer control parameters. The ABC algorithm also features good resilience, fast convergence, and great versatility. In this study, several experiments were conducted to show the productivity of the proposed ABC-based approach. The simulation results show that the proposed method is an effective optimization approach because it can achieve the global optimum in a very simple and computationally efficient way.

Challenging Approaches in Project Repository Management System

Abstract: Managing and controlling projects using traditional ways is a very difficult job. The main motive of this application is to create an automated or easy way to store as well as manage the data. In this paper, we propose a solution that is useful for students, project coordinators, and project guides to manage the project repository efficiently. The major focus is on the usability and the backup system for the stored data. The cloud infrastructure for backup is recommended in this paper. The system includes a few features such as auto-filling which would make it much easier to enter all the details, a feature to store all the previous remarks which any faculty would access. The system would also consist of the remarks on plagiarism checks on the reports. Keywords: cloud platform; plagiarism check; data management, repository, review remarks

A novel method based on fuzzy logic to evaluate the storage and backup systems in determining the optimal size of a hybrid renewable energy system

Renewable energy sources are one of the most popular sources of energy for supplying load demand in remote areas. For this purpose, a hybrid renewable energy system can be used which includes Photovoltaic panels (PVs) and Wind turbines (WTs). To meet load demand, due to the dependence of these energy sources on environmental conditions, energy storage systems such as batteries or backup systems such as diesel generators (DG) should be used. Therefore, the idea of this work is to investigate the effect of the energy storage and backup systems in a hybrid energy system (HES) with respect to environmental conditions and load demand for a remote area. Thus, with the goal of reducing costs and checking reliability based on the loss of power supply probability (LPSP), economic and sensitivity analysis is done for six cases of PV/Battery, Wind/Battery, PV/Wind/Battery, PV/DG, Wind/DG, and PV/Wind/DG. Hence, to design the optimal size of the hybrid energy system, a new technique based on the fuzzy logic controller in combination with a gravitational search algorithm (GSA) has been used. Based on this, appropriate membership functions and fuzzy rules were designed to improve the efficiency of the GSA algorithm. Also, to evaluate and validate the proposed method, the Drop-Wave function was tested and compared with other valid methods. The results show that by removing the storage system and using a diesel generator, in addition to reducing economic costs, the reliability of the system is also provided. Therefore, PV/Wind/DG system was introduced as the most cost-effective system. In this case, for LPSP equal to 0%, 1%, 2%, 5%, and 10%, the amount of total annual cost is equal to $88,853, $80,838, $78,038, $72,616, and $66,265, respectively. Also, the results showed that fuel costs and battery costs have the greatest impact on the total annual cost. In addition, pollution emission calculations including CO2, NOX, and SO2 were examined. Finally, the use of a fuzzy logic controller in the GSA algorithm increases the convergence rate, and this method can be used in other fields of engineering.

Energy Management and Voltage Control in Microgrids Using Artificial Neural Networks, PID, and Fuzzy Logic Controllers

Microgrids, comprising distributed generation, energy storage systems, and loads, have recently piqued users’ interest as a potentially viable renewable energy solution for combating climate change. According to the upstream electricity grid conditions, microgrid can operate in grid-connected and islanded modes. Energy storage systems play a critical role in maintaining the frequency and voltage stability of an islanded microgrid. As a result, several energy management systems techniques have been proposed. This paper introduces a microgrid system, an overview of local control in a microgrid, and an efficient EMS for effective microgrid operations using three smart controllers for optimal microgrid stability. We designed a microgrid consisting of renewable sources, Li-ion batteries, the main grid as a backup system, and AC/DC loads. The proposed system control was based on supplying loads as efficiently as possible using renewable energy sources and monitoring the battery’s state of charge. The simulation results using MATLAB Simulink demonstrate the performance of the three proposed microgrid stability strategies (PID, artificial neural network, and fuzzy logic). The comparison results confirmed the viability and effectiveness of the proposed technique for energy management in a microgrid which is based on fuzzy logic controllers.

Techno-economic assessment of a hybrid microgrid using PSO

In Hybrid micro grid Renewable source offers a cost-effective and reliable solution for utilizing the power generation. As we are going to provide the combination of renewable energy sources with Energy storage system and diesel generator as a back-up System. For Wind and Solar energy (Wind Speed, Temperature and irradiance) were taken on annual and regional basis. Here we are going to consider four cases (Generation with respect to Load), by using Partial Swarm Optimization (PSO) technique on the basis of economic and reliability aspects to minimize the Cost of Electricity (COE) and to maximize Loss of Power Supply Probability (LPSP). Three regions are chosen for the techno-economic assessment of the Hybrid Micro grid. The performance of the hybrid micro grid considered in these three regions is assessed in two aspects economical and reliability aspects. Four Case studies are considered for the effective assessment of the micro grid performance under various circumstances. The contribution of the renewable is analyzed for a typical load Profile.

A failure detection method of remote disaster recovery and backup system

Failure detection is one of the basic functions of building a reliable disaster recovery backup system. Aiming at the application-level disaster recovery backup failure detection problem, this paper analyzes the remote disaster recovery center architecture and failure detection hierarchy, and predicts the arrival time of cross-domain heartbeat information through the back propagation neural network based on particle swarm optimization (PSO-BP). When the actual timeout is reached, the active Auxiliary Detection (AD) is used to improve the correctness of failure detection, and finally the effectiveness of method PSO-BP-AD is verified through simulation.

A Multiple Emergency Ventilator as Backup Solution in Pandemic: A Specifically Designed and Dimensioned Device.

Goal: To provide a Multiple Emergency Ventilator (MEV) as backup in case of shortage of ICU ventilators and for use in camp hospitals. Methods: MEV provides the same oxygen mixture and peak inspiratory pressure (PIP) to 10 patients. These specifications were fixed: i) gas supply and plugs to double-limb intubation sets compatible to existing systems; ii) fluid-dynamics with no pressure drop and almost complete patients’ uncoupling; iii) individual monitoring of inspiratory and expiratory pressures and flows and control of their timing; iv) easy stocking, transport, installation with self-supporting pipes. Results: A Bell-Jar System (BJS) design permitted to safely fix PIP based on Archimedes’ law. The main distribution line was based on 2” stainless steel pipes assuring the required mechanical properties and over-dimensioned for fluidics. The Windkessel of the BJS and pipeline dead-volumes is 75.65 L and in the worst case of the instantaneous demand of 5 L by 10 patients (0.5 L each) shows an adiabatic PIP drop limited to –6.18%, confirming the needed uncoupling. Consequently, patients’ asynchrony is permitted as needed by pressure-controlled volume-guaranteed and assisted-ventilation. Conclusions: Although MEV is proposed as a backup system, its features may cover the whole set of ventilation modes required by ICU ventilation.

Deep Learning-Aided Synthetic Airspeed Estimation of UAVs for Analytical Redundancy With a Temporal Convolutional Network

A synthetic air data system (SADS) is an analytical redundancy technique that is crucial for unmanned aerial vehicles (UAVs) and is used as a backup system during air data sensor failures. Unfortunately, the existing state-of-the-art approaches for SADS require GPS signals or high-fidelity dynamic UAV models. To address this problem, a novel synthetic airspeed estimation method that leverages deep learning and an unscented Kalman filter (UKF) for analytical redundancy is proposed. Our novel fusion-based method only requires an inertial measurement unit (IMU), elevator control input, and airflow angles while GPS, lift/drag coefficients, and complex aircraft dynamic models are not required. Additionally, we demonstrate that our proposed temporal convolutional network (TCN) is a more efficient model for airspeed estimation than the renowned models, such as ResNet or bidirectional long short-term memory (LSTM). Our deep learning-aided UKF was experimentally verified on long-duration real flight data and has promising performance compared with the state-of-the-art methods. In particular, it is confirmed that our proposed method robustly estimates the airspeed even under dynamic flight conditions where the performance of conventional methods is degraded.

Emergency Operation in the Power Supply Domain According to ISO 26262

The automotive industry is currently driven by the megatrends electrification, automated driving, and connectivity. To cope with these trends, new functionalities and electric and/or electronic systems must be developed, which require a safe power supply by the power supply system. This leads to increased functional safety requirements for the power supply system, particularly regarding availability. Fault tolerance measures can be implemented to address a safety goal specifying a safety-related availability requirement. In this case, emergency operation (EO) may be necessary to reach a defined safe state. The definitions and examples provided in ISO 26262 focus on cold redundancy, whereby the backup system is not engaged during nominal operation. The objective of this paper is to evaluate EO in the context of ISO 26262 in detail and map the results to an exemplary power supply system architecture implementing cold redundancy. In general, the EO is considered to be free from unreasonable risk even though the actual automotive safety integrity level (ASIL) capability of the item is lower than the initially specified ASIL rating for the hazard due to its timing restrictions. To determine the maximum permissible duration of EO, not just random hardware faults shall be considered; additionally, systematic effects shall be considered. Furthermore, an EO may be entered due to transient faults potentially causing temporary EOs – introducing the necessity of an EO recording, e.g. by accumulating the time of all temporary EOs.

Software implementation of the enterprise protection system

The article proposes the implementation of a specific information system for ensuring the in-formation security of the enterprise. The peculiarities of the international standard ISO/IEC-15408, which is a methodology of tasks, assessments and a catalog of IT security requirements have been studied and analyzed. The specifics of the application of general security criteria have been defined and the use of Active Directory services has been proposed as an example of the implementation of General Criteria at the enterprise. The advantages of the Active Directory service in comparison with the Workgroup have been determined. Step-by-step construction of a fault-tolerant enterprise data protection system has been offered. A feature of the proposed system is the fault tolerance of the directory service, which is ensured by deploying servers – domain controllers in each domain. The article defines the main tasks of the proposed data pro-tection system, including the comprehensive coverage of management functions, the efficiency of use of computer and telecommunications equipment and software, and the adaptability of the functional and instrumental structure of the system to the features of the managed object. The proposed complex data protection system consists of a number of interconnected components. A mandatory component of setting up a comprehensive protection system is the organization of a backup system for critical databases, which includes planning a backup schedule for various servers. To manage access rights, user groups have been added, taking into account the specifics of the company's work, and setting policies makes it possible to limit access to data on the company's file servers in accordance with different levels of access to information. The imple-mentation of research materials into the practice of solving applied tasks aimed at implement-ing a data protection system at enterprises has been confirmed by acts of practical application at the enterprise Medical Center Consilium Medical LLC.

Comparative analysis of modern fault tolerance technologies

On-demand cloud applications is one of the rapidly developing technologies that highly demanded on the market. With the increase of computer systems and requirements for real-time business intelligence, potential customers of such services turn to providers of «computing on demand» services. In the data centers that used for such services, computer systems face a large amount of processed data, which in turn leads to an imbalance in the load and provokes system failures. With infrastructure as a service (IaaS) usage, customers expect efficient performance of their tasks at an optimal price. In situation, when a client submits a task for work, it is deployed on a computer system in the data center of the service provider and there is no a hundred percent assurance that task would be completed and not failed because of lack of resources or software failure. Fault tolerance and high availability issues are currently the most acute in that field. The modern set of software tools for providing fault tolerance is quite wide. In general, they are all called to ensure the trouble-free operation of the computer system, but in fact they have significant differences in conceptual terms. High availability solutions provide fully automated failover to a backup system so that users and applications can continue working without disruption. HA solutions must have the ability to provide an immediate recovery point. At the same time, they must provide a recovery time capability that is significantly better than the recovery time that you experience in a non-HA solution topology. Analyzed and compared modern fault tolerance and high availability technologies. Compared modern models of High Availability system and tools for its implementation. Identified the shortcomings of modern models and tools for fault tolerance implementing. Developed recommendations for the usage of approaches that would help to eliminate reviewed shortcomings in different cases.

Safety-Related Availability in the Power Supply Domain

The automotive industry is currently driven by the megatrends electrification, automated driving and connectivity. To cope with these trends, new functionalities and electrical and/or electronic (E/E) systems need to be developed and deployed. Independent of the implementation of E/E systems, their power input shall be ensured by the power supply system as a shared resource – leading to increased functional safety requirements for power supply systems. If the loss of an item’s functionality can lead to a hazardous event, a safety goal (SG) specifying a safety-related availability (SaRA) requirement is derived. Thereby, switching to passive mode typically cannot be considered a safe state. To address an SG specifying a SaRA requirement, fault avoidance, fault forecasting and/or fault tolerance measures can be applied. In the case of fault tolerance measures implemented by redundancy, which leads to fail-active behavior, the performance of the backup system during nominal operation and after the first fault can be further refined. In this study, SaRA in the context of ISO 26262 is evaluated in detail and mapped to an example of the power supply domain.

Simulation & Performance Analysis of Stand-by Distributed Generation System

The engineering fraternity faces the formidable challenge to cope with the exponential rise of energy demand simultaneously with the depleting reserves of fuel and environmental issues. With the development in technology and the rising demand for supply of electricity, diesel-based power generation is being used as a standby or emergency to feed this demand and at the time of unavailability of other sources. In case of emergency or as a backup system diesel-based power generation is considered in this thesis. A simulation model of diesel engine along with governor and exciter unit is developed in MATLAB/SIMULINK. The simulation performance is analyzed for different operating conditions with various resistive, inductive and capacitive loads. The exhaustive simulation results show the good dynamic and transient performance with voltage and frequency. The parameters of the machine are selected to achieve the desired electrical supply with a controlled voltage and frequency for 10%-80% loading conditions. The controller parameters (such as time constants, gains and coefficients) of the governor and automatic voltage regulator (AVR) are selected and tuned for a good transient and steady-state performance. The simulation results show a satisfactory performance in terms of efficiency, generated voltage, generator speed and frequency.y.

USE OF METHANE IN CLOSED-LOOP LIFE SUPPORT SYSTEMS FOR SPACE MISSIONS

The paper discusses the use of methane (generated in the process of oxygen recovery from carbon dioxide released by the crew during its hydrogenation in the Sabatier reaction, with subsequent extraction of 61% of oxygen through electrolysis of the resultant water) in a regenerative life support system for crews on space missions. It demonstrates that the methane resulting from Sabatier reaction can be used both for pyrolysis in order to return the resulting hydrogen into this reaction so as to extract 100% of oxygen from carbon dioxide, and for producing food protein for life support in space. The use of methane pyrolysis was enabled by new technologies which allowed lowering the process temperature down to 500–700°C and obtaining the easy-to-remove carbon. It provides recommendations for designing space systems for methane pyrolysis. The paper makes the case for use of the existing processes for industrial production of protein from methane using methanotrophic bacteria in the production of food protein for space food rations, determines the balance of a closed-loop methanotrophic reaction, provides calculation basis and recommendations for designing space systems for methanotrophic production of food protein. Development of a system for food protein production from methane will enable its use as one of the systems for providing food on the Moon and Mars, as well as a backup system in space transportation missions. Key words: space missions, crew life support, СО2 hydration, methane pyrolysis, methanotrophic bacteria, food protein.