scholarly journals Modeling Coupled Nonlinear Multilayered Dynamics: Cyber Attack and Disruption of an Electric Grid

Complexity ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-19
Author(s):  
Marc Mangel ◽  
Jimmie McEver

We study the consequences of cyberattack, defense, and recovery in systems for which a physical system is enabled by a cyber system by extending previous applications of models from the population biology of disease to the cyber system and coupling the state of the cyber system to the physical system, using the synchronous model for the electric grid. In analogy to disease models in which individuals are susceptible, infected, or recovered, in the cyber system, components can be uncompromised and vulnerable to attack, uncompromised and temporarily invulnerable to attack, compromised, or reset and thus not able to contribute to the performance of the physical system. We model cyber defensive countermeasures in analogy to the adaptive immune system. We link the physical and cyber systems through a metric of performance of the physical system that depends upon the state of the cyber system using (i) a generic nonlinear relationship between the state of the cyber system and the performance of the physical system and (ii) the synchronous motor model of an electric grid consisting of a utility with many customers whose smart meters can become compromised, in which a steady state in the difference in rotor angles is the metric of performance. We use the coupled models, both of which have emergent properties, to investigate two situations. First, when an attacker that relies on stealth compromise is hidden until it is either detected during routine maintenance or an attack is initiated. The probability that compromise remains undetected declines with time and the level of compromise increases with time. Because of these dynamics, an optimal time of attack emerges, and we explore how it varies with parameters of the cyber system. Second, we illustrate one of the Electric Power Research Institute scenarios for the reverse engineering of Advanced Metering Infrastructure (AMI) by coupling the synchronous motor equations for the generator and utility to the model of compromise. We derive a canonical condition for grid failure that relates the level of compromise at the time of detection of compromise and the dissipation parameter in the synchronous motor model. We conclude by discussing the innovative aspects of our methods, which include (i) a fraction of decoy components in the cyber system, which are not connected to the rest of the cyber system or the physical system and thus do not spread compromise but increase the probability of detection of compromise, (ii) allowing components of the cyber system to return to the un-compromised state either temporarily invulnerable or immediately vulnerable, (iii) adaptive Defensive Counter Measures that respond in a nonlinear fashion to attack and compromise (in analogy to killer T cells of the immune system), (iv) a generic metric of performance of the physical system that depends upon the state of the cyber system, and (v) coupling a model of the electric grid to the model of compromise of the cyber system that leads to a condition for failure of the grid in terms of parameters of both compromise and the synchronous motor model, directions for future investigations, and connections to recent studies on broadly the same topics. We include a pseudocode as an Appendix and indicate how to obtain R script for the models from the first author.

2018 ◽  
Vol 22 (1) ◽  
pp. 156-159
Author(s):  
O.V. Bulavenko ◽  
L.R. Ostapiuk ◽  
V.O. Rud ◽  
A.S. Voloshinovskii ◽  
T.S. Maliy

The growth of the frequency of postpartum purulent-inflammatory diseases requires the development of new approaches to their early diagnosis and treatment. The purpose of the study is to choose the optimal time for manual vacuum aspiration in patients with postpartum endometritis and to control the state of patients after it, using the method of fluorescence spectroscopy. The results of treatment of 392 patients who were on inpatient treatment in the gynecological department №2 of the City Clinical Maternity Hospital №2 were analyzed. Of these, 120 patients were selected for the diagnosis of which, in addition to the standard algorithm, the method of fluorescence spectroscopy was included. Manual vacuum aspiration was performed in 96 cases (80,0%). In 15% of patients, after vacuum-aspiration of the uterine cavity, blood serum tests using the method of fluorescence spectroscopy were carried out in dynamics. In 92,8% of them, an increase in fluorescence intensity and a shift of lmax in the short-wave region was observed, which was a reliable sign of improving the condition of the patients. Thus, the improvement of the state of patients after vacuum aspiration was confirmed at the appropriate level, using the method of fluorescence spectroscopy, which is a reliable method of diagnostics of postpartum purulent-inflammatory diseases.


Author(s):  
L. Bondarenko

The immune system is central to ensuring the consistency of the body's homeostasis. The state of the body's natural resistance is determined by a set of non-specific protective mechanisms. Lymphocytes and phagocytes are actively involved in maintaining immunity. Lymphocytes recognize the antigens of pathogenic microorganisms, and phagocytes absorb and destroy the pathogens themselves. During the weaning of piglets from sows there is a decrease in the protective forces of their body. During this period, the natural resistance of the piglets is reduced due to the stressful situation caused by changing conditions of confinement, the transition to full feed and lack of sows. The immune system of weaning pigs is relatively weak, so when exposed to environmental and technological stressors, they become susceptible to various diseases. The use of probiotic drugs stimulates the activity of the immune system, prevents stress and immunodeficiency. One of these probiotics is the probiotic of domestic production Protecto-active. It w observed the the influence of the probiotic Protecto-active on the indices of nonspecific resistance of the young pigs organism to the growth. An increase in bactericidal activity of blood serum by 12.10% (P <0.05) and lysozyme activity of blood in the piglets of the experimental group was increased by 3.71% compared to control, which indicates the activation of the body's defenses and the increase in adaptive capacity. An important step in the study of the influence of the probiotic Protekto-active on the state of the immune system is to determine the phagocytic activity of neutrophils, phagocytic index and phagocytic number. In the experimental group of piglets that were fed the probiotic Protecto-active, we found an increase in leukocyte phagocytic activity by 9.0% (P <0.001), a phagocytic index by 51.7% (P<0.001) and a phagocytic number by 24.8% ( P <0.01) compared with the control group. Thus, using a probiotic Protecto-active, all indicators of phagocytosis increase: the number of phagocytes increases, their ability to capture microorganisms and increases their digestive capacity, it increases the bacterial and lysozyme activity of blood serum, which is positively reflected in the immunobiosity. Key words: probiotic, phagocytosis, phagocytic index, phagocytic number, phagocytic activity of leukocytes, cellular immunity, piglets


2019 ◽  
Vol 23 (1) ◽  
pp. 110-113
Author(s):  
K. E. Ishcheikin ◽  
V. V. Petrushenko ◽  
D. I. Grebeniuk ◽  
O. M. Zatserkovna ◽  
L. M. Malyk ◽  
...  

The aim of the work was to study the dynamics of changes in the immune system indices and antioxidant protection when fluoroquinolones are included in the treatment regimen for acute edematous pancreatitis. The study included 86 patients with a diagnosis of acute edematous pancreatitis. Group I (n=40) consisted of patients who received treatment according to national and local standards and protocols, group II (n=46) — patients who additionally received fluoroquinolones as part of a comprehensive treatment. The control group consisted of 48 conditionally healthy people in whom laboratory and instrumental diagnostics were carried out similarly to those in patients with acute pancreatitis. According to the purpose and objectives of the study, the state of the immune system and the antioxidant defense system was studied. In patients with acute pancreatitis, changes in the indicators of the immune status were revealed, manifested by the formation of a secondary immunodeficiency with the addition of an autoimmune component. The traditional scheme of pharmacotherapy of acute pancreatitis without the use of antibiotics made it possible to partially correct the indicators of immune status. The use of ciprofloxacin in the complex pharmacotherapy of acute pancreatitis contributed to the normalization of the studied parameters. Thus, the use of fluoroquinolones in the complex pharmacotherapy of acute pancreatitis made it possible to effectively normalize the state of the immune system, cytokine and antioxidant statuses.


2014 ◽  
Vol 700 ◽  
pp. 678-681
Author(s):  
Yu Lan Li ◽  
Tie Zhu Zhang ◽  
Hong Zhao ◽  
Ji Zhang

The paper gives a brief introduction of the permanent magnet synchronous motor (PMSM). The author gives the mathematical model under the simplified conditions and the PMSM rotor and stator impedance matrix. Besides, the author used AMESim to build a synchronous motor model on the basic of hysteresis current control strategy and set the parameters. A simulation was carried out and advantages and disadvantages of hysteresis current control strategy were analyzed.


Author(s):  
I Yu Ezdakova ◽  
O V Kapustina ◽  
E V Popova ◽  
A G Grigoriev ◽  
V M Kovaikina

2020 ◽  
Vol 22 (Supplement_1) ◽  
pp. S93-S95
Author(s):  
Jonathan M Samet

Abstract Implications: This commentary addresses the state of the evidence on tobacco products, nicotine, and COVID-19. The evidence of the effects of smoking on respiratory infections and the immune system in general are examined and the current understanding of tobacco products and risk for SARS-CoV-2 infection and the course of COVID-19 is addressed.


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