Model Of Protection System Research Articles

Improvement of vibration protection of ship machines and mechanisms based on the use of dynamic stiffness compensators

The purpose of this study is the theoretical justification for improving vibration protection of ship machines and mechanisms based on the use of dynamic stiffeners. The main disadvantage of existing vibration protection devices is the impossibility of resolving the objectively existing contradiction: their efficiency is achieved with a minimum total stiffness of the suspension and, at the same time, to limit the mobility of the mechanism protected from vibration, the stiffness of the elastic elements must be sufficiently high. Design solutions of dynamic vibration dampers are proposed with spring-loaded inertial masses coaxially located relative to the main elastic element of the suspension, which vibrate in antiphase relative to vibrations of the object protected from vibrations. Design schemes of dynamic vibration damper with stiffness compensation developed on the basis of provisions of automatic control theory are presented. Based on the analysis of the developed theoretical assumptions, the main factors affecting the value of the vibration isolation coefficient and allowing to obtain a dynamically stable oscillatory system are determined. The main results of preliminary mathematical modeling of vibration protection system using the model of dynamic damper of low mass vibrations are given. The result of the research is confirmation of the prospects of the proposed technical solutions and the possibility of practical implementation of a full-fledged solution to the problem of protecting ship machines and mechanisms from vibrations.

MATHEMATICAL METHODS IN CYBER SECURITY: CLUSTER ANALYSIS AND ITS APPLICATION IN INFORMATION AND CYBERNETIC SECURITY

The huge number of information threats and their complexity prompts research and modeling of new methodologies and information protection systems. The development and improvement of information and cyber security systems includes the creation and processing of mathematical models using information technologies. This article is a follow-up study on the application of mathematical methods and technologies in cyber security, namely: methods of cluster analysis. The modern development of computer technology and the growth of their power have contributed to the wide implementation of Data Mining algorithms for processing large volumes of information in various fields of society and science, in particular in the field of cyber security. Cluster analysis allows the set to be divided into subsets, so that the elements of each subset are similar to each other, and the elements of different subsets are the most different. This provides an opportunity to eliminate the shortcomings of the qualitative approach in assessing information risks. The paper reviews scientific sources regarding the applied aspect of the application of clustering methods in security systems, because timely forecasting of possible incidents allows you to manage information risks and make effective decisions to ensure confidentiality, availability and integrity of information. The stages of the clustering procedure are characterized, the issues of choosing the distance measure and the similarity measure for the objects under study are highlighted. The comparative characteristics of the most popular methods of cluster analysis are presented: the “nearest neighbor” algorithm, “k-means”, “fuzzy c-means”, “cosine similarity”, their advantages and disadvantages are defined. This study can be useful and used in the educational process of students of the specialty 125 “Cyber security and information protection”.

Crop Security Model for Improvement in Agricultural Productivity Using Iot: Smart Farming

Most of the time in agriculture field, crops ravaged by local animals that leads to huge losses for the farmers. It’s very difficult for farmers to barricade entire fields and monitors continuously. Here the crop protection system model is developed for the farmers to prevent the crops from the animals. The model adopts the Arduino Uno based system and uses wired security that gives the shock to animals if they are approaching the field. The fire sensor is also used in the model to detect fire issues. In such situations, the microcontroller will turn ON the motor if there is a fire that interns intimate the farmers through mobile application. The temperature sensor and humidity sensors are also used in the model to provide the details of temperature and soil moisture of the field. The experimental values obtained by the model ensure complete safety of crops from animals and from fire thus protecting the farmer’s loss. In addition, mobile applications are also developed to provide the details of parameters such as temperature, moisture, water levels to farmers.

Protection Design and Effectiveness Verification of High-temperature Fire for Civil Aviation Emergency Locator Transmitter

Considering the coupling between the heat of emergency locator transmitter and the external high-temperature fire environment, a thermal protection system for external insulation and internal heat absorption is proposed. The external insulation layer consists of flexible nanofiber heat insulation film and quartz ceramics to withstand the thermal impact of the external environment. The internal heat absorption layer is composed of microcapsulated paraffin, which is used to absorb the heat transmitted through the insulation layer and the heat generated by emergency locator transmitter. Using the enthalpy method to establish a transient heat transfer mathematical model of thermal protection system, and the protection performance of the system in high-temperature fire is analyzed. The calculation results show that the system can withstand a high-temperature fire for at least 15 minutes, during which the temperature of emergency locator transmitter is controlled below 60℃. After the fire is over, under the coupling of the waste heat of the incoming system and the heat of emergency locator transmitter, the temperature of emergency locator transmitter continues to rise to a maximum of 107℃. Then, as the influence of the waste heat of the incoming system weakens, the temperature of emergency locator transmitter gradually decreases. Finally, the accuracy of the simulation model and the effectiveness of the thermal protection system are verified through destructive experiments.

Study on the Occupational Injury Protection System for Takeaway Riders and Other New Industry Practitioners

The rapid development of digital technology has given birth to new employment patterns with the typical characteristics of network platforms and high flexibility, whose features make the labor relations recognition standards designed for the characteristics of traditional employment methods reflect the limitations and ambiguity of the system when applied to the new employment patterns, leading to the lack of occupational injury protection for employees in the new industry. The solution to this problem lies in adjusting and transforming the existing lagging institutional arrangements to adapt to the changes in the labor market in the new era. According to the experience of domestic and foreign systems, there are three possible protection paths: the work injury insurance model, the commercial insurance model, and the new occupational injury protection system model. Due to the limitations of the first two models, the third model is more in line with the current needs of occupational injury protection for employees in the new industry. In the specific system design, it is necessary to fully protect the realization of workers' rights and interests, as well as to maintain the enthusiasm for the economic development of the new industry, and to provide continuous, efficient, and enforceable legal system protection for the employees of the new industry.

A specific modeling of ground protection system for wind power plants

This paper presents specific combined protection of grounding systems that can be applied for wind power plants. The proposed prototype design is a combination of the ferrite ring technique, surge arrester models, as well as voltage surge protector, which impacts dampen tension more effectively by building a dedicated line with a separate model. The proposed model is 100 m in width with a depth of 2 m from the soil which is based on the IEC-61643-12 study. The transmission line approach model is used to obtain a description of the behavior of lightning occurring in the soil. The simulation results show the proposed design can be applied effectively.

Аналитическое выражение для аппроксимации силы трения виброзащитного механизма сиденья оператора

In mathematical modeling of dynamic and vibration protection systems of operators of construction and road machines, it is necessary to take into account the damping properties of the mechanisms. Accounting for the friction force in mathematical models is often performed using a coefficient, according to the viscous friction model. In more complex models, it is common to use a well-known expression in which the functions of the exponent and hyperbolic tangent are present, and the independent parameters are the Coulomb and separation friction forces, the separation friction rate, and the coefficient of viscous friction. This expression is used in a well-known mathematical package. However, the well-known expression does not accurately approximate the experimental friction curves. In the present work, an alternative expression for the total friction force has been supplemented. The refinement made it possible to apply a new formula for the entire range of change in the velocity argument and more accurately reproduce the characteristic shape of the experimental friction characteristics. For the new expression, complementary formulas were obtained that establish the relationship between the input parameters and a number of others that have a clear and simple physical meaning of the parameters. A comparison was made of the generally accepted and proposed expressions according to experimental data, graphs of the relative error were constructed. Also, a comparison of two expressions of the total friction force was made, as an example, on a dynamic model of forced oscillations of a concentrated mass on a moving base. The comparison results showed a significant discrepancy between the generally accepted expression in comparison with the proposed one, in terms of the total friction force, as well as a discrepancy in the amplitudes of relative displacements and absolute mass accelerations obtained on the dynamic model. The proposed expression can be used to approximate the total friction force in mathematical models of dynamic vibration protection systems for operator seats.

Fault Diagnosis Method of Intelligent Substation Protection System Based on Gradient Boosting Decision Tree

In order to improve the efficiency of the devices’ fault diagnosis of the protection systems of intelligent substation, a fault diagnosis method based on a gradient boosting decision tree (GBDT) was proposed. Using the integrated alarm information, the device self-checking information, the link information of generic object-oriented substation event (GOOSE) and sampled value (SV) and the sampling value information generated during the fault of the protection system, the fault feature information set is constructed. According to different fault characteristics, the protection system faults are classified into simple faults and complex faults to improve the diagnosis efficiency. Using GBDT training rules, a fault diagnosis model of protection system based on GBDT is established and fault diagnosis steps are given. This study takes a 110 kV intelligent substation in southern China as an example, to verify the effectiveness and accuracy of the proposed fault diagnosis method, and compared it with the existing methods in terms of the accuracy. The diagnostic accuracy in the case of false alarms and the case of multiple faults are verified. The results show that the method can meet the practical engineering application.

Digital Protection Technology of Cultural Heritage Based on ArcGIS Geographic Information Technology Algorithm

In order to improve the effect of digital protection of cultural heritage, this paper analyzes the spatial and temporal characteristics of cultural heritage with the support of ArcGIS technology, conducts research on ArcGIS’ geographic information technology algorithm, and improves the algorithm with the support of digital technology. Moreover, this paper combines the watermark algorithm to digitally mark cultural heritage to improve the copyright effect of cultural heritage. In addition, this paper proposes a topological integrity verification method based on weak watermark vector geographic data to improve the reliability of digital processing of cultural heritage, and build an intelligent cultural heritage digital protection system model. The research results show that digital protection technology of cultural heritage based on the ArcGIS geographic information technology algorithm in this paper can play an important role in the digital protection of cultural heritage.

Medium-Term Forecast of Government Spending on the Unemployment Social Protection System in Russia in the Conditions of Economic Recession.

—A simulation model of the Russian unemployment social protection system is developed and used to study the impact of the economic crisis caused by the COVID-19 pandemic, demographic processes, and the increase in retirement age on federal spending on unemployment benefits. Trends of overall and registered unemployment across various socio-demographic groups in 1992–2020 are analyzed, with special attention paid to periods of economic recession and recovery. The identified patterns are used to develop modeling scenarios. Calculations show that in the unfavorable scenario government spending on unemployment benefits will increase many times. As a possible solution to the problem, it is proposed to convert the unemployment social protection system to insurance principles. The time frame in which reforming the system would be less expensive for the federal budget is defined.

“Invisible” children: A multiple case study on the experiences and protection of hospital-stranded children

BackgroundHospital-stranded children are defined as children who are left by parents in medical settings for over six months. These children, who legally are not classified as orphans, are excluded from existing permanent placement policies in China. Yet, little is known about this vulnerable population of children. ObjectiveThis study explores the experiences of hospital-stranded children and the causes for their plight, and examines the strengths and weaknesses of existing child protection practices in medical settings. MethodsUsing a multiple-case design, 20 hospital-stranded children from three children's hospitals in a first-tier Chinese city were included in this study. Sixteen hospital personnel participated in semi-structured interviews. Interview findings, case records, and field observations were analyzed using a thematic analysis approach. Current child protection practices were analyzed through a child protection system model. ResultsThe children in this study were well cared for by the hospitals, but their rights to provision, participation, and protection were violated due to the lack of a national child protection system. Three key weaknesses of child protection practices were identified: underreporting of suspected cases, delayed action after reporting, and inadequate follow-up services. The ineffectiveness of the national child welfare system and the family-oriented cultural values in China also created barriers to the protection of hospital-stranded children. ConclusionsThe findings suggest an urgent need for a national child protection system. Professional child protection training for healthcare workers and collaboration among departments within and outside hospitals are also necessary to offer a systematic protective network for hospital-stranded children.

Optimal spraying task assignment problem in crop protection with multi-UAV systems and its order irrelevant enumeration solution

Creating a team of crop protection unmanned aerial vehicles (UAVs) for a scheduled spraying task over fields is a method that seeks to overcome the various limitations of using individual UAVs. However, given some of the issues with pesticide spraying operations involving multiple UAVs (multi-UAVs), such as differences in hardware, irregular field borders, spray drift, and operator proficiency, assigning spraying sub-tasks to multi-UAVs during crop protection is more important and more complex than for other homogeneous multi-agent systems in common use. In this study, a mathematical model of a heterogeneous multi-UAV crop protection system is established. Based on this model, an optimal spraying task assignment problem (OSTAP) for multi-UAVs used in crop protection is proposed. To solve this problem, it is converted to an equivalent combinatorial problem. The order irrelevant enumeration solution (OIES) algorithm is proposed where time and space complexities are more efficiently implemented on a horizontal comparison among OIES, equal task assignment (ETA), sequential task assignment (STA), discrete particle swarm optimisation (DPSO), and a full permutation algorithm. Numerical simulation with a six-UAV system showed that OIES could solve OSTAP in a finite time using C++ in the Visual Studio environment and performed efficiently and accurately. Finally, with the proposed OIES, an OSTAP application software was developed as a visualisation of an OSTAP solution. With this application, a spraying test with the five-UAV system was carried out to determine the effectiveness of OIES in an actual pesticide spraying operation. Test results showed that OIES performs best with these algorithms, which takes only 51.3% of the operating time taken by ETA and it requires fewer flights.

Оценка быстродействия системы противоаварийной автоматической защиты

Introduction. Emergency protection systems are an indispensable element of modern automated control systems for fire and explosion hazardous technological processes. The protection of personnel, process equipment and the environment depends on their timely operation. Therefore, the methodology for quantifying the performance of the Emergency Protection System in the design and analysis is of undoubted practical interest. Targets and goals. The goal is to develop an algorithm and methodology for quantifying the response time of the protection system in the pre-emergency mode of operation of a technological facility. The tasks include the formation of mathematical models for calculating the time parameters of the elements that make up the Emergency Protection System. Methods. Methods of mathematical analysis and modeling of emergency protection systems are used. Results and discussion. The functions of the Emergency Protection System and the regulatory requirements for their performance depending on their safety class of hazardous production facilities are considered. A generalized algorithm for the formation of the Emergency Protection System is considered, taking into account the requirements for its speed. Using the typical structure of the Emergency Protection System as an example, an expression was obtained for the delay time when it performs the functions of an alarm and the operation of automatic shut-off and shut-off devices. According to technical sources, the approximate time parameters of the elements of the Emergency Protection System are given. The method of quantitative assessment of the response time is considered using the example of an emergency protection system designed to detect gas contamination of a production facility due to depressurization of process equipment, the formation of control signals when the concentration of combustible gases reaches a pre-explosive level, the activation of an alarm, and the operation of valves that block the access of combustible gas to a process facility. Mathematical expressions for calculating the parameters are determined, which allow estimating the total response time of the Emergency Protection System and its compliance with the safety condition for the normatively set time. Conclusions. The considered technique can be used in practice for a preliminary assessment of the response speed of the Emergency Protection System, as well as in the educational process for carrying out practical and laboratory work in the study of industrial automation systems to prevent fire and explosion. Keywords: emergency protection system, protection response time, pre-emergency mode of operation, accident.

Reliability Modeling and Analysis of Reactor Protection System Based on FPGA

In order to establish a reactor protection system reliability model based on the field programmable gate array (FPGA) to provide effective analysis and verification methods for system safety, this study adopts the fault tree and stochastic Petri net (SPN) models to perform reliability modeling and analysis for the single channel of CANDU reactor shutdown system 1 (SDS1). The analysis by fault tree model provides the minimal cut set. With the top event probability taken as the system fault probability, and in consideration of the fault detection, maintenance and periodic testing, the probability of rejection of the system is obtained by the stochastic Petri net model simulation. The results show that both the fault tree and state space representation are limited to a certain extent, while the stochastic Petri net can reflect the impact of fault detection and periodic tests on the reactor protection system, dynamically present the system reliability, and avoid the problem of state space explosion. Therefore, the stochastic Petri net model established in this study is suitable for the reliability modeling of the reactor protection system.

Three-dimensional modeling of in-ground cathodic protection systems with deforming anodes

The design of sacrificial cathodic protection (CP) systems conventionally involves steady-state assumptions, which means design parameters are considered constant during the in-service life of CP systems. In contrast, it is evident by experimental observations (including field measurements) that cathodic protection is a transient process due to variations in electrolyte properties such as seasonal changes in electrical conductivity of soil, depletion of anodes, and formation of corrosion deposits on anode material surface, to name a few. The lack of practical time-dependent models on this critical issue is apparent in the literature; accordingly, in this study, a pseudo transient electrochemical model is adopted to highlight the transient behavior of cathodic protection systems and investigate key differences with steady-state behavior. For the sake of demonstration, the developed model is used to simulate the time-dependent performance of a sacrificial anode bed for cathodic protection of screw-pile foundations. The methodology proposed in this study can be used by corrosion engineers to improve and optimize the design of CP systems and numerically estimate the performance of sacrificial anodes and the level of protection over time.

Dynamic Modeling of Reactor Protection System in Nuclear Power Plant for Reliability Evaluation Based on State Transition Diagram

Reliability assessment of a digital dynamic system using traditional Fault Tree Analysis (FTA) is difficult. This paper addresses the dynamic modeling of safety-critical complex systems such as the digital Reactor Protection System (RPS) in Nuclear Power Plants (NPPs). The digital RPS is a safety system utilized in the NPPs for safe operation and shut-down of the reactor in emergency events. A quantitative evaluation reliability analysis for the digital RPS with 2-out-of-4 architecture using the state transition diagram is presented in this paper. The study assesses the effects of independent hardware failures, Common Cause Failures (CCFs), and software failures on the failure of the RPS through calculating Probability of Failure on Demand (PFD). The results prove the validity of the proposed method in analyzing and evaluating reliability of the digital RPS and also show that the CCFs and longer detection time are the main contributions to the PFD of digital RPS.

Ways to improve OSH management system efficiency

Problem statement . High level of occupational injuries at enterprises in the construction industry makes necessary to conduct studies aimed at improving the effectiveness of the OSH management system with regard to a systematic approach. However, the OSH management system has not yet been studied from these perspectives. The purpose of the article is to research the improvement methods to identify the risks of dangerous situations, taking into account action or inaction of an employee and an employer, by developing the mathematical model of a labor protection system and measures to increase its effectiveness, as well as by implementing mechanisms to stimulate employers to improve working conditions and workers to meet the requirements of regulatory legal acts on labor protection. The mathematical model of labor protection system has been developed, its efficiency has been evaluated, methodology and criteria for the quantitative assessment of accident risks, based on indicators how the employee and the employer follow labor protection legislation, have been improved. Scientific novelty and practical significance . The studies performed by the authors slightly changed the approach to the assessment of production risk, as they associated it with the participants in the labor process, whose actions or negligence lead to its occurrence, which made it possible to assess the true situation of labor protection at enterprises in the industry. It was based on the results of the experiments, the indicators were obtained using the risk-based approach and database of statistics on injured people in the industry, which is constantly updated. The mathematical model of the labor protection system has been developed. The size of the indicator of economic motivation is mathematically justified as the way of stimulating the employer to create safe working conditions and observe the requirements of regulatory and legal documents on labor protection.

Mixed Weibull distribution model of DC protection system based on entropy weight method

By analyzing the blocking event of DC converter station of the State Grid Corporation in recently ten years, it can be concluded that the sampling system failure, secondary circuit fault, board fault, host fault, etc. of the protection system caused more than 10% of the DC system blockings, which have seriously threatened the normal operation of DC system. Towards this end, this paper makes a statistical analysis of the operation defects of high-voltage direct current (HVDC) transmission protection in Hubei Company in the past five years. A mixed Weibull distribution model method based on entropy weight method is proposed. By using this method, the reliability curve and average defect interval time (MTBF) of the DC protection system are obtained. Combined with the actual situation of the converter station, the DC protection system of the converter station is evaluated, which provides an important guiding basis for the subsequent maintenance, system transformation, and replacement of the converter station.

Dynamic Modeling of Reactor Protection System in Nuclear Power Plant for Reliability Evaluation Based on State Transition Diagram

Reliability assessment of a digital dynamic system using traditional Fault Tree Analysis (FTA) is difficult. This paper addresses the dynamic modeling of safety-critical complex systems such as the digital Reactor Protection System (RPS) in Nuclear Power Plants (NPPs). The digital RPS is a safety system utilized in the NPPs for safe operation and shut-down of the reactor in emergency events. A quantitative evaluation reliability analysis for the digital RPS with 2-out-of-4 architecture using the state transition diagram is presented in this paper. The study assesses the effects of independent hardware failures, Common Cause Failures (CCFs), and software failures on the failure of the RPS through calculating Probability of Failure on Demand (PFD). The results prove the validity of the proposed method in analyzing and evaluating reliability of the digital RPS and also show that the CCFs and longer detection time are the main contributions to the PFD of digital RPS.

Integration of Fire Protection Systems Based on the Digital Automatic Model

The development of refineries increases the number and scale of fires and accidents, which cause damage both to the facilities themselves and to the surrounding buildings and structures, lives and health of people, the environment. That is why increasing the level of fire protection systems at refineries remains one of the most important components of ensuring the protection of the population from anthropogenic threats. The article presents the results of the analysis of accidents and fires at oil refineries (refinery) for 2015–2019. The issue of necessity to integrate fire protection system at the refinery is considered. The process of creation and functioning of the automated integrated fire protection management system is described in the article. This system is a new approach to solving the issue of safety of industrial facilities of oil refining industry. Creation of a new model of fire protection system based on digital automatic system is described. The article considers the scheme of generalized structure of digital automatic machine and graphs of digital automatic machine of automated integrated fire detection and monitoring system. The developed technology makes it possible to process the incoming signal contained in cyclograms into an intermediate form for synthesis of digital automatic machines by means of innovative tools.