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Blackouts in maritime activities can cause propulsion loss and dangerous maritime conditions. Bayesian risk analysis is applied to ship blackout incidents in this study to improve understanding and reduce risks. Using Fault Tree Analysis (FTA), a Bayesian Network (BN) model incorporates fuel quality, lubricating oil quality, sensor error, injector error, and mechanical defects to estimate blackout probability. The model analyses how hazards and their interactions affect this situation using probabilistic inference. Sensitivity analysis identifies variables that affect blackout probabilities and prioritises risk mitigation solutions. Based on prior and posterior probabilities, ‘Automatic Voltage Regulator Failure’ (0.03 prior, 0.17 posterior), ‘Rotor Mechanical Fault’ (0.03 prior, 0.15 posterior), and ‘High Cooling Water Temperature’ (0.03 prior, 0.13 posterior) are the top three blackout causes. Other significant variables include ‘Switchboard Line Failure,’ ‘Faulty Fuel Pump,’ ‘Rotor Open Circuit,’ and ‘Temperature Sensor Failure’ in relative amounts. Bayesian risk analysis can identify and minimise marine blackout concerns, giving decision-makers a comprehensive framework for informed decision-making and proactive risk management. This research emphasises blackout accidents’ importance, improving maritime transportation safety and reliability. [ABSTRACT FROM AUTHOR]

This paper presents findings from an online questionnaire that collected experiences from the Facebook outage on October 4th, 2021, an event that affected approximately three billion users around the globe. The purpose of the study is to contribute to recent discussions digital disconnection and digital wellbeing by using an extraordinary event of involuntary disconnection as point of departure. Our research questions were: Where were people when the services shut down, what did they think and what did they do? What correlations can be found between usage/attitudes to social media and the experiences of the outage? How can the outage of October 4th be understood as a snapshot of our cultural condition? The questionnaire was distributed to 463 Swedish university students and 191 responses were received. Our analysis shows how the involuntary disconnection caused by the outage was an event that highlights the ambivalence of digital life. It also points to some correlations between general social media use and attitudes, and the experiences and activities during the outage. The paper ends with a discussion on the implications that these findings may have for further research into digital disconnection. [ABSTRACT FROM AUTHOR]

Intro: Communication is understood to be a pillar of democracy. Therefore, governments around the world enact laws which make it easier for politicians to communicate with their constituents. However, some governments also restrict this ability during campaign seasons as a way of unclogging the media. In the United States, congressional election blackout dates are periods in which politicians are not allowed to engage in mass unsolicited mailing of political advertising. Because the prohibition only applies to unsolicited media, we theorize that we should see the transition from one type of communication to another. Methods: To test this effect, we created a database containing all tweets by all Members of Congress from the last three Congresses. Results: We find that immediately during the blackout periods, members of Congress substantially increase the number of tweets they post. Discussion: We conclude that Members of Congress are strategic in their ability to exchange communication outlets. [ABSTRACT FROM AUTHOR]

Analysis of various accident scenarios is vital for the safety assessment of nuclear fuel storage facilities. The accidents in the storage vault due to loss of cooling are generally considered highly uncertain since the accident progression is slow (in comparison to reactors) and allows time for remedial activities to the operator. In the present work, numerical simulations of different accident scenarios have been carried out for a short duration to understand the situation better. Thermal aspects of accident conditions such as failure of the suction blower, drying of cooling water at the chiller, and combined effect of both accidents were investigated. The airflow inside the ventilated enclosures due to the failure of the blower and the rise in inlet air temperature is analyzed numerically. The temperature distributions inside the vault and the rise in temperature of the sub-assemblies and magazines have been studied. The key mechanisms of heat transfer, which take part in nuclear fuel storage vault for post-accident conditions, were identified. The study will be helpful to classify various accident conditions based on their thermal implications and the model developed can be used to design passive cooling systems. [ABSTRACT FROM AUTHOR]

Copyright of Revista Electrónica de Psicología Iztacala is the property of Facultad de Estudios Superiores Iztacala and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Electric vehicles (EVs) are being introduced in Rwanda and becoming attractive for different reasons. For instance, these types of vehicles can help decrease air pollution and noise emissions. In addition, it presents an alternative to combustion engines, given the increased price of fuel resources in Rwanda and around the world. This paper presents a tool tailored to optimize the design of an electrical charging station serving small-sized electric vehicles, utilizing the algorithm to assist in sizing stand-alone mopped charging stations. The developed tool is based on the toolbox EventSim from MathWorks, which permits the combination of the simulation of discrete events (such as the arrival of customers at the station) with continuous states (such as the simulation of the charging process). The required PV power was estimated by utilizing solar resources, for the location, from renewables. Ninja. The number of customers arriving at the existing oil station is normalized to estimate the energy requirements of the mopped fleet. A Poisson distribution was proposed to model the battery discharge upon arrival, and different related parameters were evaluated through a sensitivity analysis to identify their effects on the performance of photovoltaic charging station. For the testing values, the station parameters were changed by ±25% to determine the impact of key design parameters on station performance, as well as other satisfaction measures such as average waiting time and average queue length. With a 25% increase in photovoltaic panels, the blackout period decreases by 2.12%, while a 25% decrease in photovoltaic panels causes an increase of 2.18% in the blackout period. Utilizing the energy management system (EMS), the waiting time was reduced by 8%.

Fluctuations in electricity demand can lead to inefficiencies in diesel generators (DEG) and potentially trigger blackouts, as experienced by PT Indolakto. This study aims to identify the performance parameters of a 2 MW DEG and formulate strategies to prevent blackouts caused by the 2 MW DEG at PT Indolakto. The research used data collection techniques including field observations, interviews, literature studies, and performance test analysis. The results showed that the efficiency of the 2 MW DEG at load reached 44%, indicating there is still reserve power. An overload of 21% from the generator's capacity resulted in a blackout and a system frequency drop of 13.4 Hz from the normal frequency. Although the 2 MW DEG has adequate efficiency, optimization is necessary to prevent blackouts. One strategy is to use the 2 MW DEG as a system reserve for critical loads. [ABSTRACT FROM AUTHOR]

Piped drinking water supplies are exposed to a range of threats. Changing hazard situations arise from climate change, digitisation, and changing conditions in the power supply, among other things. Risk and crisis management adapted to the hazard situation can increase the resilience of the piped drinking water supply. Analogous to the risk management system, this article describes a methodology that ranges from hazard analysis with the prioritisation of 57 individual hazards to vulnerability assessment with the help of balance sheet structure models (BSM) and the planning and implementation of measures to increase the resilience of the piped drinking water supply in a targeted manner. The work steps mentioned build on each other and were tested using the case study of a water supply company in Saxony (Germany). As a result, priority hazards are identified, the remaining supply periods and replacement and emergency water requirements are determined as part of the vulnerability assessment, and finally, planning principles for increasing resilience are documented. The methodology focuses primarily on practicable application by water supply companies. [ABSTRACT FROM AUTHOR]

The Southern Cameroon Interconnected Network (SIG) is depicted as a large-scale power system that has shown significant instability due to a series of blackouts in recent years. These blackouts are primarily attributed to major disruptions in transmission lines and energy deficits between supply and demand. The imbalance between power supply and demand necessitates the grid to operate near its stability limits, increasing the risk of blackouts. The necessity of investigating the dynamics of SIG behavior in response to observed contingency situations serves as the primary motivation for this study. To achieve this objective, the SIG was modeled using saturated generators with ZIP static loads. Through Newton-Raphson based power flow calculations, voltage magnitude profiles of the grid were obtained for each generation scenario. An N-1 contingency consisting of a standard Newton-based continuation power flow (CPF) analysis has identified line 5–6 as the most frequent worst case of line outage. Additionally, a short-term transient analysis was conducted under three-phase short-circuit, line outage and generator outage scenarios. In the event of a short-circuit, the Mangombe-225 bus experienced the most significant impact. Concerning line outages, line 1–5 had the most adverse effect on the grid's frequency stability. However, generation outages had a lesser impact on frequency stability compared to other disturbances. Lastly, modal analysis revealed that the grid exhibited weak stability with a critical mode identified at a frequency of 4.0267 Hz, exceeding typical values. This underscores the necessity of damping the grid oscillations for enhanced stability.

Power systems are the most complicated networks that play a crucial role in daily lifestyles. To operate such systems in a stable condition, several control and protection strategies are required. Despite preventative measures, power systems still experience issues and breakdowns like power outages. However, severe and unanticipated conditions might cause damage to the entire system and causes blackout. In this article we studied the analysis of the significant blackouts and cascading failures that have been happened in Pakistan in last few years. The authors proposed a new infrastructure for Pakistan energy sector by introducing advanced energy storage system and cutting edge technology like Vehicle-to-Grid (V2G) technology that make the existing power system robust against these phenomena. The advanced energy storage systems include like solid- state batteries that play a vital role to balance supply and demand, while V2G enables electric vehicles to contribute to grid stability. The potential of these technologies is helpful to improve the grid stability and facilitate a sustainable energy transition. The role of various electric companies in Pakistan power infrastructure has also been discussed after an occurrence of such unplanned events in power system. It has been noted that the main cause of power outages is fluctuation in frequency and voltage collapse. Finally, various solutions have been proposed to overcome these problems and make sure the reliability and stability of power grid against blackout phenomena.

During the Russian-Ukrainian war, mass power outages occurred in Ukraine, caused by Russian attacks on civilian infrastructure, namely on the generating and distribution capacities of the power system. The risks associated with such outages cover not only the issue of uninterrupted operation of the economy directly, but also more complex aspects related to cyber security. The impact of such outages on the cyber security of information and communication systems is considered, namely, the second-order effects, such as interruptions with information observability, violation of the integrity of the protection infrastructure, overloading of monitoring teams and response to false alarms. All these factors alter the threat landscape for the system and must be considered in security policy and during the threat modeling process accordingly. An analysis of hidden cyber security risks arising in connection with massive power outages was conducted. Possible approaches to taking such risk factors into account when modeling threats, as well as methods of countermeasures, are given. [ABSTRACT FROM AUTHOR]

A grid blackout is an intractable problem with serious economic consequences in many developing countries. Although it has been proven that microgrids (MGs) are capable of solving this problem, the uncertainties regarding when and for how long blackouts occur lead to extreme difficulties in the design and operation of the related MGs. This paper addresses the optimal design problem of the MGs considering the uncertainties of the blackout starting time and duration utilizing the kernel density estimator method. Additionally, uncertainties in solar irradiance and ambient temperature are also considered. For that, chance-constrained optimization is employed to design residential and industrial PV-based MGs. The proposed approach aims to minimize the expected value of the levelized cost of energy ( L C O E ), where the restriction of the annual total loss of power supply ( T L P S ) is addressed as a chance constraint. The results show that blackout uncertainties have a considerable effect on calculating the size of the MG's components, especially the battery bank size. Additionally, it is proven that considering the uncertainties of the input parameters leads to an accurate estimation for the LCOE and increases the MG reliability level. [ABSTRACT FROM AUTHOR]

Due to the significant gap between demand and supply of electricity, power utility companies employ rolling blackouts, in which the power supply to different regions is cut-off periodically for a specified duration. However, this causes increased user inconvenience as consumers are left without power; also, a large undesirable blackout may occur if the circuit breakers are not opened in time. To solve this problem, this paper has developed a more pragmatic approach in which a power threshold limit is imposed on households during times of deficit power supply. This paper presents five algorithms designed to allocate load thresholds to households in a fair manner. Some of these algorithms perform the worst (high violations) in some time slots and best (minimal violations) in other slots, but none guarantees minimal mean violation across all the time slots. In this regard, this paper has also developed a novel optimal algorithm that ensures a minimal violation percentage of the allotted thresholds across all time slots in all the households of a neighbourhood. It also employs multiple heuristics for threshold allocation, thereby preventing household starvation. The algorithms are evaluated on a real-world dataset. Its mean violation across all the houses goes as low as nearly 45% and is minimum across all the time slots. It performs all the algorithms used for power limit distribution. This result demonstrates the effectiveness of the developed technique in the implementation of the brownout scheme in practise. [ABSTRACT FROM AUTHOR]

Copyright of Engineer Military Bulletin / Muszaki Katonai Közlöny is the property of National University of Public Service and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The decision-making of generator start-up sequence plays a pivotal role in the power system restoration process following the blackout. In this paper, an optimized deep Q-learning network (DQN) algorithm is proposed to address this challenge. The generator start-up process is modeled as a Markov Decision Process (MDP) based on its characteristics. The DQN is tasked with deciding both the generator start-up sequence and the corresponding restoration path. To address the limitations of DQN, such as low exploration efficiency and slow convergence, the study incorporates the Artificial Potential Field (APF) algorithm to refine the reward function of it. This integration results in the development of the F-DQN (APF-DQN) algorithm, which enhances training efficiency. The effectiveness of this proposed method is demonstrated through the IEEE 39-bus test system. The results reveal that the DQN algorithm is capable of efficiently solving the model of the generator start-up sequence after the blackout. Moreover, the F-DQN algorithm exhibits superior learning efficiency, faster convergence, and higher-quality optimal solutions compared to the DQN. This paper also discusses the applicability of this method under partial blackouts. When compared to other decision-making algorithms, the proposed method offers a restoration scheme that is both time-efficient and results in increased electricity generation. [ABSTRACT FROM AUTHOR]

The complexities in modern power systems are increasing daily with the integration of renewable sources and an increasing number of power system components such as lines, buses, transformers, FACTs devices, and many more. The complexity and the limitations in power transfer capabilities for meeting the power consumptions under the contingency condition may occur in the system. The power system contingencies may lead to blackouts and complete system failure. Therefore, power system contingency analysis is a very emerging topic in power system analysis. This paper identifies some previous contingency analysis research and finds the different research persons and journal sources that publish related articles in this field through a bibliometric analysis. [ABSTRACT FROM AUTHOR]

Purpose: To date, no study has evaluated effects of varying brightness settings on image quality from flexible ureteroscopes submerged in saline. The aim was to evaluate blackout and whiteout occurrences in an in-vitro kidney calyx model. Material and methods: We evaluated a series of contemporary flexible ureteroscopes including the Storz Flex-Xc and Flex-X2s, Olympus V3 and P7, Pusen 7.5F and 9.2F, as well as OTU WiScope using a 3D-printed enclosed pink in-vitro kidney calyx model submerged in saline. Endoscopic images were captured with ureteroscope tip placed at 5 mm,10 mm and 20 mm distances. The complete range of brightness settings and video capture modes were evaluated for each scope. Distribution of brightness on a grayscale histogram of images was analyzed (scale range 0 to 255). Blackout and whiteout were defined as median histogram ranges from 0 to 35 and 220 to 255, respectively (monitor image too dark or too bright for the human eye, respectively). Results: Blackout occurred with the P7, Pusen 7.5F, 9.2F and WiScope at all distances, and V3 at 20 mm - with lowest brightness settings. Whiteout occurred with Flex-X2s, V3 and P7 at 5 mm and 10 mm, as well as with V3 and P7 at 20 mm - mostly with highest brightness settings. The Flex-Xc had neither blackout nor whiteout at all settings and distances. Conclusion: Blackout or whiteout of images is an undesirable property that was found for several scopes, possibly impacting diagnostic and therapeutic purposes during ureteroscopy. These observations form a guide to impact a urologist’s choice of instruments and settings. [ABSTRACT FROM AUTHOR]

Today humanity is going through a period of great upheavals and rapid changes in every sphere of life, including the environment, that inevitably lead to general destabilisation and disruptions. In the latest novel by Rumaan Alam, apocalyptic Leave the World Behind (2020), a crisis appears to reshape our closest bonds and forge new ones. This story of an invisible terror deals with cataclysmic but mysterious events that shut down the communication networks we over-rely on, and sees an almost overwhelming sense of uncertainty, panic and increasing anxiety. Isolated in the remote holiday house with the Vermont stone kitchen tops and night-lit swimming pool, a couple of New Yorkers and their teenage children are looking forward to taking a rest from the routines of city life when catastrophe strikes. In addition to the major theme of the threat of human extinction, Leave the World Behind explores the relationship between class and race and the complexities of parenthood and solitude during an unspecified disaster. Those issues are included in the context of the global problem of anthropogenic impacts on the environment. At the same time, Alam demonstrates how habituation to the ongoing crises in the modern world, including social-ecological transformations, affects the understanding of a severe situation people are facing and ways to prevent it: they have increasing tolerance for the absurd. The suspenseful, provocative and prescient book, Leave the World Behind, captures the generalised panic of 2020, the year of a global outbreak of coronavirus. As a kind of end-of-the-world fiction, the novel is full of moments of exquisite recognition and reappraising of our attitudes the article discusses. [ABSTRACT FROM AUTHOR]

Piped drinking water supplies are exposed to a range of threats. Changing hazard situations arise from climate change, digitisation, and changing conditions in the power supply, among other things. Risk and crisis management adapted to the hazard situation can increase the resilience of the piped drinking water supply. Analogous to the risk management system, this article describes a methodology that ranges from hazard analysis with the prioritisation of 57 individual hazards to vulnerability assessment with the help of balance sheet structure models (BSM) and the planning and implementation of measures to increase the resilience of the piped drinking water supply in a targeted manner. The work steps mentioned build on each other and were tested using the case study of a water supply company in Saxony (Germany). As a result, priority hazards are identified, the remaining supply periods and replacement and emergency water requirements are determined as part of the vulnerability assessment, and finally, planning principles for increasing resilience are documented. The methodology focuses primarily on practicable application by water supply companies.

Recent history demonstrates that threat has no borders, though risk does, due to national and regional differences in vulnerabilities and exposure landscapes. The difference between well and poorly managed threat is striking. Inequalities in preparing for threats as a function of their type are still apparent. Compared to more concerning electromagnetic interference threats, the impact of geomagnetic disturbance (GMD) on power grid operation is not well studied. The need for detailed research of GMD negative impacts is expected to broaden awareness. The amplitude of geomagnetically induced currents (GICs) is treated as a uniform measure of danger that can be processed by various stakeholders. Hence, methods for increasing the accuracy of GIC representation are presented in this paper. A low-entropy signal is defined and it is shown that the feature of low signal entropy can be used for increasing the accuracy of the measurement equipment. At the end, a full-system view of GMD impact on power grid operation is given.

An undeclared war has been going on in Ukraine for more than one year. Defeated at the front, Russia resorted to massive shelling of energy facilities with the aim of leaving Ukrainians wit­hout electricity and heat during the winter. As reported, since October 10, the Russians have fired more than a thousand missiles and drones at Ukrainian energy facilities. The shelling on November 23, 2022 led to a system crash — a blackout occurred. For the first time in the history of Ukraine, all of the country’s nuclear power units were shut down. In conditions of lack of light and non-wor­king refrige­rating chambers, the storage conditions of thermolabile immunobiological drugs became a new test for the medical community and patients. As you know, immunobiological drugs, which are widely used in the treatment of various rheumatological disea­ses, require strict storage conditions in the temperature range from +2 to +8 °С. Under blackout conditions, it is difficult for Ukrainian patients to maintain optimal storage conditions for these drugs. The analysis of the studies showed that the majority of patients do not comply with the requirements for the storage of thermolabile drugs, even with the constant presence of light and electricity. Experts indicate that more and more thermolabile drugs are becoming available, and in most cases, these medications are dispensed to ambulatory patients. More thermolabile drugs are becoming avai­lable, and in most cases, these medications are dispensed to ambulatory patients. However, there is no regulation once medications are dispensed to patients and little is known with regard to what happens during transport and home sto­rage. Previous studies suggest that these drugs are improperly stored. Future studies should focus on clinical consequences and possible solutions. It is recommended for Ukrainians to follow the rules and conditions of sto­rage of heat-labile medicinal products during blackouts/emergency and stabilization blackouts.

A grid blackout is an intractable problem with serious economic consequences in many developing countries. Although it has been proven that microgrids (MGs) are capable of solving this problem, the uncertainties regarding when and for how long blackouts occur lead to extreme difficulties in the design and operation of the related MGs. This paper addresses the optimal design problem of the MGs considering the uncertainties of the blackout starting time and duration utilizing the kernel density estimator method. Additionally, uncertainties in solar irradiance and ambient temperature are also considered. For that, chance-constrained optimization is employed to design residential and industrial PV-based MGs. The proposed approach aims to minimize the expected value of the levelized cost of energy (LCOE), where the restriction of the annual total loss of power supply (TLPS) is addressed as a chance constraint. The results show that blackout uncertainties have a considerable effect on calculating the size of the MG’s components, especially the battery bank size. Additionally, it is proven that considering the uncertainties of the input parameters leads to an accurate estimation for the LCOE and increases the MG reliability level.

Purpose: Hyperventilation is considered a major risk factor for hypoxic blackout during breath-hold diving, as it delays the apnea breaking point. However, little is known about how it affects oxygenation, the diving response, and spleen contraction during serial breath-holding. Methods: 18 volunteers with little or no experience in freediving performed two series of 5 apneas with cold facial immersion to maximal duration at 2-min intervals. In one series, apnea was preceded by normal breathing and in the other by 15 s of hyperventilation. End-tidal oxygen and end-tidal carbon dioxide were measured before and after every apnea, and peripheral oxygen saturation, heart rate, breathing movements, and skin blood flow were measured continuously. Spleen dimensions were measured every 15 s. Results: Apnea duration was longer after hyperventilation (133 vs 111 s). Hyperventilation reduced pre-apnea end-tidal CO2 (17.4 vs 29.0 mmHg) and post-apnea end-tidal CO2 (38.5 vs 40.3 mmHg), and delayed onset of involuntary breathing movements (112 vs 89 s). End-tidal O2 after apnea was lower in the hyperventilation trial (83.4 vs 89.4 mmHg) and so was the peripheral oxygen saturation nadir after apnea (90.6 vs 93.6%). During hyperventilation, the nadir peripheral oxygen saturation was lower in the last apnea than in the first (94.0% vs 86.7%). There were no differences in diving response or spleen volume reduction between conditions or across series. Conclusions: Serial apneas revealed a previously undescribed aspect of hyperventilation; a progressively increased desaturation across the series, not observed after normal breathing and could heighten the risk of a blackout. [ABSTRACT FROM AUTHOR]

College drinkers commonly report blacking out (i.e., alcohol-induced amnesia), and those who drink with the intention to blackout are at risk for harmful consequences. Drunkorexia (i.e., restriction of calories on planned drinking days) is a high-risk behavior potentially associated with blacking out. Informed by the Theory of Planned Behavior (TPB), this study explores blackout experiences and intentions to blackout association with drunkorexia. College students (n = 2335) who primarily identified as female and White participated via an online survey. Participants received a $3 coupon for completion of the study. Consistent with the literature, 40% and 60.7% of participants reported experiencing blackouts and drunkorexia, respectively, in the last year. Informed by the TPB, a structural equation model assessed whether more frequent blackout experiences (IV) were related to drunkorexia behaviors (DV1) and alcohol behaviors (DV2), and whether there was a significant indirect effect through blackout intention. The model fit the data well (CFI =.98, TLI =.95), which suggests that more frequent blackout experiences relate to more drunkorexia experiences (R2 =.04) and higher levels of alcohol consumption (R2 =.44). In addition, the relationship between blackout experiences and drunkorexia flows through intentions to blackout (i.e., a significant indirect effect). Findings are consistent with TPB, which suggests that intentions predict health behavior. Future interventions should consider modifying intentions and other possible TPB constructs to minimize high-risk alcohol consumption and drunkorexia behaviors. • College students who intend to blackout are likely to engage in alcohol consumption, suggesting that intentions to experience blackouts are high among college students who frequently engage in heavy drinking and experience alcohol-related consequences. • Lifetime history of blackouts relates to current drunkorexia behaviors, and frequency of recent drinking relates to future intention to blackout. • This study confirms that intentions predict negative health behavior, including drunkorexia, a riskier alcohol consumption behavior, among college students. [ABSTRACT FROM AUTHOR]

The massive blackout that occurred in August 2003 left over 50 million people in the northeastern and midwestern parts of the United States without electricity and caused billions of dollars in economic losses. This event highlighted the importance of sustainable and resilient energy infrastructure. Our study examines the impact of this blackout on the sustainability of financial markets by analyzing the liquidity and information asymmetry of U.S. stocks listed on major exchanges. Our results show that the blackout had a negative impact on the financial market's liquidity, as evidenced by a significant widening of bid–ask spreads and a decrease in the market quality index. We also find an increase in information asymmetry during the blackout period, as measured by higher realized spreads. Furthermore, our study reveals that the blackout had a border impact on global financial markets and the negative effect on liquidity persisted even after two weeks. [ABSTRACT FROM AUTHOR]

The necessary precautions should be taken in order to prevent service interruption during the maintenance and repairing of electricity networks. Among these measures, emergencies that may occur in the network should be foreseen, hazard scenarios should be created, and solutions should be developed. If these are not done, a blackout, which first follows the local regions and eventually results in the collapse of the national electrical network, may take place. In this study, the national blackout of Turkey that occurred on 31 March 2015 is examined. The information about Turkey's electrical infrastructure and its energy policies was provided, as well as the reliability assessment criteria for power systems and examples of significant blackouts that occurred worldwide. The direct relation between line voltage and system frequency was provided with mathematical derivation by using real data taken from a local industrial zone. Then, a case study is presented to demonstrate this direct relation. The causes, development process, and consequences of the blackout are discussed in detail, and some recommendations are offered to increase the security of the electrical infrastructure and to prevent future occurrences while ensuring the sustainability of the system. [ABSTRACT FROM AUTHOR]

Aim: The article aimed to present the essence of the systemic approach to business continuity management (BCMS - Business Continuity Management System) and to determine the level of maturity of business continuity systems implemented in small and medium-sized enterprises about selected groups of external threats, corresponding to current economic, political and legal conditions. Project/methodology/approach: The subject of this study is an analysis based on the available resources in the literature and the results of the conducted empirical study. Findings: As a result of the literature study, it has been proven that organizations are exposed to many threats that affect business continuity to varying degrees. The fundamental element of organizational prevention at the operational level is the business continuity plan, which defines response mechanisms in the event of an incident or crisis that negatively affects the stability of implemented projects. The analysis of the research results indicated that the primary response mechanism established in modern organizations transfers the burden of the effects of the crisis to employees, as it is related to the performance of professional duties using remote communication methods and techniques. Research limitations/implications: The primary research limitation was the difficulty in obtaining a representative research sample, which is why it was decided to limit the scope of the research and carry it out in enterprises belonging to high-tech industries. Bearing in mind that the scope of the study referred to conditions which, due to the increased uncertainty of the general (intermediate) environment, are subject to changes and improvement of modern management systems, it is recommended to conduct the research again in other economic sectors. Expanding the study's scope will allow the development of a catalogue of good practices, including a more comprehensive catalogue of threats to the continuity of modern business organizations. Originality/value: The article presents previously untested mechanisms ensuring business continuity about current threats – blackout and energy lockdown. The analyses contained therein may be the basis for improving internal crisis response systems, especially in small and medium-sized enterprises. [ABSTRACT FROM AUTHOR]

Recent history demonstrates that threat has no borders, though risk does, due to national and regional differences in vulnerabilities and exposure landscapes. The difference between well and poorly managed threat is striking. Inequalities in preparing for threats as a function of their type are still apparent. Compared to more concerning electromagnetic interference threats, the impact of geomagnetic disturbance (GMD) on power grid operation is not well studied. The need for detailed research of GMD negative impacts is expected to broaden awareness. The amplitude of geomagnetically induced currents (GICs) is treated as a uniform measure of danger that can be processed by various stakeholders. Hence, methods for increasing the accuracy of GIC representation are presented in this paper. A low-entropy signal is defined and it is shown that the feature of low signal entropy can be used for increasing the accuracy of the measurement equipment. At the end, a full-system view of GMD impact on power grid operation is given. [ABSTRACT FROM AUTHOR]

Cascading effects in the power grid involve an uncontrolled, successive failure of elements. The root cause of such failures is the combined occurrence of multiple, statistically rare events that may result in a blackout. With increasing digitalisation, power systems are vulnerable to emergent cyber threats. Furthermore, such threats are not statistically limited and can simultaneously occur at multiple locations. In the absence of real-world attack information, however, it is imperative to investigate if and how cyber attacks can cause power system cascading failures. Hence, in this work we present a fundamental analysis of the connection between the cascading failure mechanism and cyber security. We hypothesise and demonstrate how cyber attacks on power grids may cause cascading failures and a blackout. To do so, we perform a systematic survey of major historic blackouts caused by physical disturbances, and examine the cascading failure mechanism. Subsequently, we identify critical cyber-physical factors that can activate and influence it. We then infer and discuss how cyber attack vectors can enable these factors to cause and accelerate cascading failures. A synthetic case-study and software-based simulation results prove our hypothesis. This analysis enables future research into cyber resilience of power grids.

The objective of this paper is to enhance the frequency resilience and wind penetration level of a low inertia power system by utilising frequency responsive Thyristor Controlled Series Capacitor (TCSC). In recent years, wind power integration has become prolific in numerous power grids around the world. As such, Synchronous Generators (SGs) are being substituted from the generation mix. Unlike conventional synchronous generators, variable speed Wind Turbine Generators (WTGs) generally do not participate in system frequency control without additional control strategy. When subjected to prolific wind generation and interconnection import from an adjacent grid, number of online SGs in a grid can be scant. During such a situation, a large contingency in the power importing zone may overload an AC interconnection. Consequently, the interconnection could trip due to loss of synchronism. It eventually may cause a system-wide blackout. In addition, due to the risk of network separation, non-synchronous wind penetration level is kept restricted in many power systems. To overcome these challenges, this paper proposes a frequency responsive TCSC model to increase interconnection transfer capability by reducing the line reactance. To this end, for determining optimal TCSC parameters, a strategy is outlined. Furthermore, a generalised expression is developed to find the maximum wind penetration level while maintaining the frequency response adequacy. The developed techniques are applied to a low inertia test system. Simulation results reveal that the risk of blackout is averted, and the maximum wind penetration level is significantly increased after deploying the frequency responsive TCSC.

Unreliable electricity supply is a widespread problem in developing countries. This paper examines the impact of power outages on firm productivity in East Africa, considering the effect of generator ownership in general and during blackouts. The results show large negative effects of power outages on productivity and a mitigating effect of self-generating during power outages of approximately the same size. However, self-generation is also found to generally reduce productivity due to the idle capital effect of unused generators during blackout-free times. This finding highlights that self-generation is only profitable for firms if the experienced power outages are severe enough. [ABSTRACT FROM AUTHOR]

During the Russian-Ukrainian war, mass power outages occurred in Ukraine, caused by Russian attacks on civilian infrastructure, namely on the generating and distribution capacities of the power system. The risks associated with such outages cover not only the issue of uninterrupted operation of the economy directly, but also more complex aspects related to cyber security. The impact of such outages on the cyber security of information and communication systems is considered, namely, the second-order effects, such as interruptions with information observability, violation of the integrity of the protection infrastructure, overloading of monitoring teams and response to false alarms. All these factors alter the threat landscape for the system and must be considered in security policy and during the threat modeling process accordingly. An analysis of hidden cyber security risks arising in connection with massive power outages was conducted. Possible approaches to taking such risk factors into account when modeling threats, as well as methods of countermeasures, are given. [ABSTRACT FROM AUTHOR]

This paper proposes an imputation method using a bidirectional k-nearest components search based local linear regression method. The bidirectional k-nearest-components search method selects components in the dynamic range from the missing points. Unlike the existing methods, which use a fixed-size window, the proposed method can flexibly select adjacent components in an imputation problem. The weight values assigned to the components around the missing points are calculated using local linear regression. The local linear regression method is free from the rank problem in a matrix of dependent variables. In addition, it can calculate the weight values that reflect the data flow in a specific environment, such as a blackout. The original missing values were estimated from a linear combination of the components and their weights. Finally, the estimated value imputes the missing values. In the experimental results, the proposed method outperformed the existing methods when the error between the original data and imputation data was measured using MAE and RMSE. [ABSTRACT FROM AUTHOR]

The results of simulation of a geomagnetically induced current impact on the consolidated power system of the center of Russia expected during a strong magnetic storm are represented. It is shown that a complex of factors appears during this impact that can induce the progression of a blackout: a significant decrease in voltage on a set of electrical power elements, the mass cutoff of power transmission lines under the effect of relay protection, and the dangerous heating of construction elements of power transformers. [ABSTRACT FROM AUTHOR]