Issues of the Risk-Based Approach

The purpose of the article was to analyze the problems currently standing in the way of more effective application of the risk-based approach methodology in the field of technogenic safety management. Methods — theoretical, inductive method, analysis of own experience, adopted normative legal acts, other publications. The main results of the work include the following: • despite the broadest use of the concept of “risk” in the field of technogenic safety management, there is no generally accepted interpretation of it to date; • often the evaluative concept of “risk” is mistakenly used instead of objectively existing risk factors; • quantifiably technogenic risk should be characterized by indicators of numerical nature, having vector objects, since two components should be indicated for the complete assignment of the indicator: the probability and the amount of damage; • experience shows that the methods of assessing the probabilistic component of risk indicators recommended by regulatory documents on the analysis and quantification of technogenic risk are accompanied by a very large uncertainty, therefore, instead of the traditional point statement, a more adequate method of assessment is the use of an interval approach that takes into account and allows quantifying this uncertainty; • the analysis showed that the so-called frequency approach, which is most often used to assess the probabilistic component of technogenic risk indicators, is used improperly, has no basis, since, as a rule, the phenomenon of statistical stability is not observed in the object area of the technosphere, there are no general aggregates; • in society and even among specialists, by now there is no understanding of the need to express all three components of damage from an accident (explosion/fire) in monetary terms, without which it is impossible to estimate and express the amount of total damage: — in conclusion, four key problems that hinder the more effective use of the risk-based approach methodology in the field of technogenic safety management are listed; — imperfection of the existing methodological base for the analysis and quantitative assessment of technogenic risk; — the problem of staffing in the field of technogenic risk management; — lack of national criteria for acceptable risk; — complete disregard of the problem of uncertainty of the results of the COR, the lack of methodological support for the procedure of analysis and quantification of this uncertainty. Conclusion — the efforts of the entire community of specialists-researchers, legislators, practitioners engaged in various aspects of the problem of technosphere safety management are necessary to solve the tasks specified in the article.

Development and Application of Estimation Method for the Scale of Damage in Domestic Drought

In this study, an estimation method for damage and recovery costs on account of domestic droughts was developed. The estimation method for the scale of damage was applied based on the national drought statistics generated by the Ministry of Public Administration and Security. The damage and recovery costs of domestic droughts were calculated based on the damage data of domestic droughts that occurred in 2018 and 2019. The estimation method was developed for damage costs incurred due to domestic droughts by considering the number of people affected by water supply restrictions, accommodation, and restaurants. The method for estimating recovery costs after domestic droughts was developed considering domestic disaster support, water support, water development support, equipment support, and human resource support for victims. Due to the construction of a DB of limited domestic drought damage status, the damage costs were calculated for the number of people affected by water supply restrictions, and the recovery costs were calculated for the domestic disaster and water support. The total damage costs caused by domestic droughts in 2018 amounted to 612.471 M KRW, and in Gangwon-do and Jeollanam-do, they were 218.616 M KRW in 2019, and more than 90% of Incheon metropolitan city was calculated. The total recovery costs caused by domestic droughts in 2018 were 5,994.555 M KRW, and in Gangwon-do and Jeollanam-do, they amounted to 4,882.024 M KRW in 2019, and more than 90% of Chungcheongnam-do was calculated. The difference between the damage and recovery costs of domestic droughts was approximately tenfold in 2018 and twentyfold in 2019.

LIFE ASSESSMENT OF RAILS BY CRITERION OF OCCURRENCE OF FATIGUE CRACKS

The paper presents modern concepts of the contact fatigue crack occurrence in the railhead. Numerical simulation of the contact interaction between rails and rolling stock wheels by finite elements method are presented. During the simulation, the problem was solved in elastic and elastic-plastic formulations. We considered R65 rail profile and standard railway wheels. The conditions for the rail–wheel interaction corresponded to train movement on the straight section of the track without slipping. The modern life assessment methodology involves the calculation of the material damage increment at each point of the element as the load varies over time, and subsequent summation of this damage. Upon reaching the ultimate value of the total damage, the structural element is believed to lose its load-carrying capacity, i.e. a crack is formed in it. Despite the substantial simplification of the real problem, the computational costs for the implementation of such methods for predicting the durability will be unnecessarily high. In this regard, we propose the simplified method of the durability calculation.

Research on the weapon target assignment problem in the combined air defense missile system for training simulation

In modern warfare, when the weapon system and the targets are constantly being improved and upgraded, ensuring the distribution of firepower to optimally destroy the target will help the commander to make quick and accurate decisions, thereby improving combat effectiveness. This paper proposes a method to build a command-control automatic system based on solving the weapon target assignment (WTA) problem in a combination of short and medium-range air defense missile systems so that the total damage of targets is maximum and the damage of protected area is minimum. Based on combinatorial optimization algorithms, the probability of kill, linear programming method using Hungarian algorithm, the paper presents a mathematical model of WTA and its optimal solution for short- and medium-range air defense missile systems serving the training simulation problem, thereby giving the results of evaluating the effectiveness of the algorithm.

Lobular panniculitis as a manifestation of pancreatitis. Difficulties in diagnosis

The clinical picture of lobular panniculitis associated with damage to the pancreas can vary widely, accompanied by damage to the joints and internal organs, which complicates the diagnosis of the disease. A clinical observation of a torpid course of lobular panniculitis with total damage to organs and systems is presented, which clearly illustrates the difficulties of differential diagnosis and therapy that arise in real therapeutic practice.

Forms of drug allergy and various variants of its manifestation

Lately, the problem of drug allergy is becoming more and more urgent, which is a consequence of the wide availability of drugs and the widespread use of counterfeit drugs. According to some authors, the incidence of drug allergy reaches 60%. This pathological reaction is the result of the patient's individual intolerance to one or another medication, and is not inherently its side effect. In some cases, the ingestion of a minimum dose of a drug into the body is sufficient for a severe reaction to develop. Theoretically, any drug can cause an allergy, but there is a group of certain medications, to the ingestion of which an allergic reaction develops most often - these include antibiotics of the penicillin series, sulfonamides, analgesics, some antihypertensive drugs, B vitamins. An allergic reaction can develop with lightning speed, or it can manifest itself within a day. The most common forms of drug allergy include urticaria, Quincke's edema, and itchy rash (toxidermia). The most formidable manifestations of drug allergy are anaphylactic shock and Lyell's syndrome, which manifests itself in the form of total damage to the skin and mucous membranes.

Study on Mechanical Properties and Damage Characteristics of Red Sandstone under Freeze-thaw and Load

To analyze the effects of freeze-thaw cycles and confining pressure on the mechanical properties of red sandstone, through freeze-thaw cycles and triaxial compression tests, full stress-strain curves of different freeze-thaw cycles and different confining pressures were obtained. The degradation degree of red sandstone was quantitatively considered from different mechanical parameters of ultimate stress, elastic modulus, and Poisson’s ratio. Based on summarizing the characteristics of rock under freeze-thaw and load, the total damage variable of rock was determined by the reasonable measurement of freeze-thaw damage variable and load damage variable, and a damage constitutive model under freeze-thaw and load was established. The research showed that the freeze-thaw cycles aggravate the degree of rock damage deterioration, the rock stiffness and strength were reduced, and the characteristics of plastic deformation and ductile failure were more obvious. The confining pressure inhibited red sandstone internal damage, and with the increase of confining pressure, the stiffness and strength and the plastic characteristics were increased. In the overall trend, the mechanical parameters had different sensitivity to the degradation effect of freeze-thaw cycles and confining pressure. Regardless of the increase in the number of freeze-thaw cycles or confining pressure, the strain softening modulus tended to decrease gradually, and red sandstone plastic damage became more obvious after the stress peak. The total damage evolution path of red sandstone reflected the nonlinear influence of freeze-thaw and load on the total damage propagation. The research results provide theoretical support for the improvement of the technology of the effluent coal rock in Balasu Coal Mine.

Investigation into Multiaxial Character of Thermomechanical Fatigue Damage on High-Speed Railway Brake Disc

The multiaxial character of high-speed railway brake disc thermomechanical fatigue damage is studied in this work. Although the amplitudes and distributions of temperature, strain and stress are similar with uniform and rotating loading methods, the multiaxial behavior and out-of-phase failure status can only be revealed by the latter one. With the help of a multiaxial fatigue model, fatigue damage evaluation and fatigue life prediction are implemented, the contribution of a uniaxial fatigue parameter, multiaxial fatigue parameter and out-of-phase failure parameter to the total damage is discussed, and it is found that using the amplitude and distribution of temperature, stress and strain for fatigue evaluation will lead to an underestimation of brake disc thermomechanical fatigue damage. The results indicate that the brake disc thermomechanical fatigue damage belongs to a type of multiaxial fatigue. Using a uniaxial fatigue parameter causes around 14% underestimation of fatigue damage, while employing a multiaxial fatigue parameter without the consideration of out-of-phase failure will lead to an underestimation of about 5%. This work explains the importance of studying the thermomechanical fatigue damage of the brake disc from the perspective of multiaxial fatigue.