System Analysis Model Research Articles

The double elastic foundation beam model for analysis of load transfer systems of racks and nut columns in shiplifts

The load transfer systems of racks and nut columns are important components of the rack and pinion vertical shiplifts which bear the ship chambers and transfer the ship chamber loads in special cases to the tower columns. Aiming at exploring a design based calculation method for the nut column, racks and the associated second stage embedded parts, this paper proposes the double elastic foundation beam model for both the rack load transfer systems and nut column load transfer systems by which the formulas for describing the axial distribution of internal forces and deflections of the rack, column nut and the associated second stage embedded parts are derived. The calculation method is demonstrated by the description of the application in the Three-Gorges shiplift.

Design optimization of a new supercritical CO2 single reheat coal-fired power generation system

Although supercritical CO2 (S–CO2) coal-fired paper generation systems have been studied broadly in recent years, there is still potential for further energy savings. A new system is proposed to efficiently use the waste heat of both the cooler and the boiler. The new system extends the air preheater surface area, uses the economizer to replace part of the heat load of the high-temperature recuperator, and both the evaporator and precooler are arranged before the cooler. The performance analysis model of the new system is built, and the effects of the economizer split ratio, the main compressor split ratio, and the operation load on the new system performance are investigated. The results show that the new system performance is much better than that of the reference system. Under the design condition, the boiler efficiency and the power generation efficiency of the new system are 96.3% and 49.5%, 1.1% and 2.6% higher than those of the reference system. There exist optimal split ratios for both the economizer and main compressor. The optimal split ratio of the economizer is 10%, and that of the main compressor is 70%. The power generation efficiency decreases with a decreasing operation load.

Holistic 1D Electro-Thermal Model Coupled to 3D Thermal Model for Hybrid Passive Cooling System Analysis in Electric Vehicles

Thermal management is the most vital element of electric vehicles (EV) to control the maximum temperature of module/pack for safety reasons. This paper presents a novel passive thermal management system (TMS) composed of a heat sink (HS) and phase change materials (PCM) for lithium-ion capacitor (LiC) technology under the premise that the cell is cycled with a continuous 150 A fast charge/discharge current rate. The experiments are validated against numerical analysis through a computational fluid dynamics (CFD) model. For this purpose, a comprehensive electro-thermal model based on an equivalent circuit model (ECM) is designed. The designed electro-thermal model combines the ECM model with the thermal model since the performance of the LiC cell highly depends on the temperature. Then, the robustness of the model is evaluated using a precise second-order ECM. The extracted parameters of the electro-thermal model are verified by the experimental results in which the voltage and temperature errors are less than ±5% and ±4%, respectively. Finally, the thermal performance of the HS-assisted PCM TMS is studied under the fast charge/discharge current rate. The 3D CFD results exhibit that the temperature of the LiC when using the PCM-HS as the cooling system was reduced by 38.3% (34.1 °C) compared to the natural convection case study (55.3 °C).

Modeling and operation domain analysis of wind-photovoltaic-hydrogen coupled energy block system

With the rapid development of my country’s new energy field, higher requirements have been put forward for the wind-photovoltaic-hydrogen coupled absorption and capacity configuration of the power system. Therefore, the physical nature and regular characteristics of energy conversion, storage, and coupling between wind-photovoltaic-hydrogen multi-differential energy sources are different. This article first starts from the perspective of power/energy supply and demand balance, and comprehensively considers system output, conversion efficiency, energy loss and other factors to establish a wind-photovoltaic-hydrogen coupling system analysis model. Then, according to the relationship between power and time, the system’s model operation domain is comprehensively analyzed. Finally, combined with the actual measured data of wind power and load in a certain area, using simulation software, the system’s operating domain and spatial flexibility are analyzed, and the validity of the system model constructed in this paper is verified.

A quantum-inspired model for statistical analysis of repairable systems

Extensive number of models have been proposed in literature to describe the failure-repair-failure process, with the aim of obtaining a better fit of failure data in a specific application area. This paper implements an alternative approach to model the repairable systems with the application of quantum mechanics theory. With the Hilbert structure describing the system state, a non-Hermitian time-dependent Schrodinger equation is utilized to describe the intrinsic failure process. Then a repair operator is introduced to represent the degree of repair by changing the time-dependent probability amplitudes of the system state. By this means, we developed two quantum repair models for the cases of different state restoration degree. To demonstrate the validity of the proposed models for both single and multiple systems, three real-world data sets are employed and the results show that the proposed model has better fitting performance compared with the most commonly used classical repair models. Quantum mechanism indicates its validity and practical appeal of application in industry and reliability modelling.

Research on the action mechanism of circular economy development and green finance based on entropy method and big data

PurposeBy calculating the information entropy of the indicator and measuring the amount of information in the data, this paper determines the weight of the indicator according to the impact of the relative change of the indicator on the whole.Design/methodology/approachIn order to study the action mechanism of circular economy development and green finance, based on the entropy method, this paper constructs a system analysis model based on event research.FindingsMoreover, this paper uses the analytic hierarchy process to obtain subjective weights based on expert opinions and then uses the entropy method to obtain objective weights and finally combines the two. In addition, an intelligent model is constructed based on the action mechanism of circular economy development and green finance to improve the system structure.Originality/valueFinally, this paper designs experiments to verify the performance of the system model. The research results show that the system model constructed in this paper meets the actual situation.

SIMPLIFIED ANALYSIS AND SEISMIC RESPONSE OF INTER-STORY ISOLATION SYSTEMS WITH AN ATTACHED INERTER

The inter-story isolation technology is a new control method in the field of earthquake engineering. The analysis model of the inter-story isolation hybrid control system with an attached inerter is established. The dynamic characteristic formulae of the inter-story isolation hybrid control system with an attached inerter are derived. The influence of the calculated parameters of the model on the dynamic characteristics is analyzed. The seismic response prediction formula based on the response spectrum is established and verified by time-history response analysis. The response control effect of the hybrid control system with an additional inerter and the influence of key parameters on control effect are analyzed. The results show that the inerter has a certain contribution to the control of the seismic response of the inter-story isolation structures. The proposed method can be used to predict the seismic response of the inter-story isolation hybrid control system with an attached inerter. The inerter can realize the dual control target of both displacement and acceleration. The results provide a reference for the simplified analysis methods and hybrid control of inter-story isolation systems.

Adaptive robust vulnerability analysis of power systems under uncertainty: A multilevel OPF-based optimization approach

With the growing level of uncertainties in today’s power systems, the vulnerability analysis of a power system with uncertain parameters becomes a must. This paper proposes a two-stage adaptive robust optimization (ARO) model for the vulnerability analysis of power systems. The main goal is to immunize the solutions against all possible realizations of the modeled uncertainty. In doing so, the uncertainties are defined by some pre-determined intervals defined around the expected values of uncertain parameters. In our model, there are a set of first-stage decisions made before the uncertainty is revealed (attacker decision) and a set of second-stage decisions made after the realization of uncertainties (defender decision). This setup is formulated as a mixed-integer trilevel nonlinear program (MITNLP). Then, we recast the proposed trilevel program to a single-level mixed-integer linear program (MILP), applying the strong duality theorem (SDT) and appropriate linearization approaches. The efficient off-the-shelf solvers can guarantee the global optimum of our final MILP model. We also prove a lemma which makes our model much easier to solve. The results carried out on the IEEE RTS and modified Iran’s power system show the performance of our model to assess the power system vulnerability under uncertainty.

Prospects for the Use of Information and Communication Technologies in the Provision of New Types of Insurance in the Republic of Uzbekistan

This article is devoted to the issues of effective application of advanced information and communication technologies in the insurance activities of the Republic of Uzbekistan. The author, using the example of the “Ishonch” insurance company, shows that in the modern period in the Republic of Uzbekistan the quality of the provision of insurance services is improving, as well as their quantitative indicators are growing.Purpose. The purpose of this article is to scientifically substantiate the place and role of advanced information and communication technologies in the provision of insurance services in the economic market, as well as the development of the insurance sector in the context of the development of the digital economy.Materials and methods. In the course of preparing the material for this article, the methods of system analysis, economic and mathematical methods and models, special methods of working with information systems and computer networks of various levels were used. All materials of the article are based on the use of factual material of the insurance company “Ishonch” of the Republic of Uzbekistan.Results. The article presents the author's approaches to the development of a distributed management system for the web resources of an insurance company in the global computer network of the Internet, it is proved that in the modern period the effectiveness of the functioning of insurance companies in the economic market depends on the degree of implementation of advanced information and communication technologies in their activities.In this paper, it is emphasized that the use of advanced information and communication technologies is of great importance in the development of insurance activities. In particular, the author emphasizes that the development of insurance services is achieved both by the development of existing software products, and by the development of new technological, software and information solutions based on the introduction of digital technologies.This paper shows that an information system is of great importance for the effective functioning of an insurance company, which includes a complex of interrelated subsystems providing the effective functioning of an insurance company in the economic market.Particular importance in this article is given to the use of the global Internet network. The author noted that the web representation of the insurance company on the Internet and the use of platform solutions and cloud technologies play a large role in the company's activities. In addition, the article tells about the fact that recently in the insurance business, electronic business is becoming widespread, which allows you to link together all participants in the insurance market.Conclusion. The material of this article shows that in the modern period in the insurance activities of the Republic of Uzbekistan there is a continuous process of introducing advanced information and communication technologies, contributing to the development of both the insurance sector itself and all participants in the economic market through the use of information systems, technologies, software products and new electronic services being introduced.The article notes that modern insurance companies, thanks to the development of advanced information and communication technologies, work with their clients directly, which creates benefits for both clients and insurance companies. In general, this article shows that the development of insurance activities in modern conditions is unthinkable without the use of advanced information and communication technologies and the adoption of competent management decisions.

Research on vulnerability analysis model of security accident system in petrochemical enterprises

AbstractPetrochemical enterprises store and process a large number of flammable, explosive, toxic and harmful chemicals, and their security protection systems are vulnerable. Once damaged by man‐made malicious will cause serious losses and adverse effects. Previous studies on the vulnerability of petrochemical enterprises have insufficient consideration of systematicity and uniqueness, and lack consideration of the correlation and game of vulnerability elements. In this study, from the perspective of system, the elements of the security accident system vulnerability are analyzed, and the vulnerability analysis model of security accident system is put forward by studying the interaction between the elements. Threat and exposure constitute the external vulnerability of security accident system, sensitivity and adaptability constitute the internal vulnerability of security accident system; and the threat plays a counter role with sensitivity and adaptability through exposure, which promotes the evolution of vulnerability; Moreover, the different vulnerability elements of security accident system evolve step by step, with the evolution of security accidents. Finally, an illustrative case proves the feasibility of the vulnerability analysis model proposed in this study. The results of this research enrich the theoretical research on vulnerability, provide a reference for the prevention and control of security accidents in petrochemical enterprises.

Research on Vibration Suppression Method Based on Coaxial Stacking Measurement

A dynamic analysis model of the unbalanced vibration response of a single-rotor system is established to study the corresponding mechanism of the unbalanced excitation force and vibration response caused by the deviation of the rotor mass centroid in this paper, and finally to achieve the combined rotor vibration suppression. First, the installation of multi-stage rotors during vibration was studied, and the rotor mass centroid transfer model in the rotating coordinate system was established to obtain the unbalanced excitation force vectors of the rotors at all levels based on the traditional stacking assembly method and axiality measurement. Second, the rotor unbalance excitation force vectors were substituted at all levels to establish the finite element analysis model of the single-rotor system. Finally, a simulation analysis was carried out for the stacking assembly of the three-stage rotor, and the rotor test piece was used for the vibration experiment. The results show that the optimal assembly phase of the multi-stage rotor obtained by the dynamic analysis model of the unbalanced vibration response of the single-rotor system can effectively suppress the vibration of the combined rotor.

Economic Mechanism of Optimizing the Innovation Investment Program of the Development of Agro-Industrial Production

The efficiency of innovation activities of agro-industrial enterprises is provided by the choice of the optimal innovation-investment program, which consists of a set of innovative projects and the appropriate amount of money needed for their implementation. At the same time, given the limited financial resources required for the development of production, it is important to form an optimal set of projects by allocating funds not to local projects, but to the entire innovation and investment program as a whole. In this regard, the article aims to form an effective innovation-investment program of the development of agro-industrial enterprises based on modeling the choice of the optimal set of projects of the development of new innovative products and projects of the introduction of ready innovations on the market. To achieve this goal, the following research methods were used: systems analysis, economic and mathematical modeling, abstract-logical method, graphical method. According to the research results the proposed economic-mathematical model can be used in the process of choosing an innovative strategy of the development of agro-industrial production, as well as to form targeted programs of innovative development and investment support of agro-industrial enterprises as a whole.

System analysis of resource interaction processes in the biotechnological system

The paper provides mathematical modeling of processes occurring in the biotechnological system, using the example of the interaction of functional microorganisms with contaminating microflora, which is currently a promising scientific direction. The analysis showed that there are no existing studies on this issue, as well as systematic and integrated approaches to solving this problem that allow describing the processes under consideration. Therefore, it is necessary to analyze and build a system model that reflects the full range of interactions between useful and extraneous populations of microorganisms in the production of bakery products. System analysis and mathematical modeling of microbiological processes is a complex task. It is necessary to take into account a lot of factors, such as the simultaneous flow of several non-stationary processes; a lot of state parameters, including the analysis of relationships between them; changes in real-time technological parameters, in particular the main resource, taking into account various properties of microbial populations that affect the behavior of microbiological systems (mortality, birth rate, the existence of extraneous microflora, etc.), and other factors that directly affect the quality of the finished product. These factors characterize the complexity of forming a mathematical model that allows you to take into account all the main features of the production of bakery products. The existing mathematical apparatus and the system analysis of this kind of production carried out before considered the behavior of the population of beneficial microorganisms, but did not contain an analysis of the effect of contaminating microflora on it. The problem can be reduced to a system of differential equations describing the microbiological process as a whole. To describe the General model needed to describe an unknown function, including constraints on the parameters. In addition, you must set the initial and boundary conditions and determine the coefficients of the model. The paper offers a system model for analyzing the effect of plant additives on biotechnological properties and test quality indicators. The presented system model allows you to continue the study of the issues raised in the work, by further studying its components.

Development of an algorithm for evaluation of a comprehensive risk management indicator in food safety management systems

The object of research is risk management in food safety management systems. The subject of the study is individual indicators, criteria and a comprehensive indicator of risk management for food safety. One of the most problematic areas is the lack of a common methodology for food safety risk assessment for the development, implementation and operation of food safety management systems. This leads to the fact that it is impossible to properly assess the risk groups depending on the object of management: – unintentional threats (HACCP concept – hazard analysis and critical control points); – intentional threats (concepts VACCP – vulnerability analysis and critical control points, TACCP – threat analysis and critical control points). And evaluate the overall effectiveness of the food safety management system. The study used methods of systems analysis and mathematical modeling as the main research method in all fields of knowledge. As well as a scientifically sound method of assessing the characteristics of complex systems used for decision-making in various fields of economic, managerial and social activities. The proposed in the work algorithm allows to quantify the level of risk management in the food safety management system by such groups as unintentional and intentional threats, taking into account the general indicators of the criteria and their factors. The overall criterion for unintentional threats, which are identified using HACCP principles, is determined by three criteria: microbiological threats, chemical threats and control measures, which in turn include a number of factors. The general indicator of the criterion for intentional threats, which are identified using the principles of VAССР and TAССР, is also determined by three criteria: opportunities, motivation and control measures, which in turn have a separate number of factors. The obtained algorithm allows to determine the levels of risk management and serve as an effective tool for obtaining objective information about the effectiveness of the implementation of the food safety management system. In contrast to existing methods of food safety risk assessment, which are based only on the management of unintentional threats, the proposed algorithm allows to take into account the impact of intentional threats – fraud and bioterrorism. And consider food safety risks comprehensively and develop options for improving management measures.

THE RISK PLANNING METHODOLOGICAL PRINCIPLES FOR HOUSING INVESTMENT

In many countries wordwide there is an urgent need to increase the housing level. However, a significant increase in this level is hindered by a number of factors. Among these factors, the significant risk of housing construction investing is essential. Reducing the riskiness of housing construction investing requires, among other things, the use of scientifically grounded risk planning methods in such investment. With taking this into account, the purpose of this work is to develop methodological principles for the housing investing risk planning. The study subjects were the patterns of forming the housing construction investing risks. The methodology of this study involved the use of systems analysis, economic and mathematical modeling, tools of decision theory, and technical and economic calculations. Among the results of the study, the formed input information array needed for planning the housing investing risks should be noted. This array includes the following main blocks: information on the available regulatory and legal support for housing construction; information on potential developers, intermediaries, and other entities investing in housing construction (particularly on the occurrence of risky events’ frequency and scale in their activities); information on potential investment objects (such as their preliminary estimated costs, consumer characteristics, construction terms); information on the concluding agreements’ conditions and procedure between the housing construction investment subjects. The indicator system for retrospective assessment in housing construction investing risk is proposed. In particular, the following indicators groups are included in this system: actual frequency indicators of risky events’ occurrence in the investment entities’ activity in the previous period(s); specific indicators of the risky events’ occurrence scale in the investment entities’ activities in the previous period(s); relative indicators of the risky events’ occurrence scale in the investment entities’ activities in the previous period(s). Also, this indicators system was supplemented by a number of generalizing indicators. The sequence of the risk planning process in housing construction investing for all the main participants of the process is proposed. For the investors particularly, this sequence contains the following sequential actions: a set of situations in which the construction object may appear is formed; the probability for each of these situations is estimated; the expected value of the economic benefit from the housing purchase in each situation is set; the mathematical expectation calculation of the value of economic benefits from the housing purchasing is made; the coefficient of variation is calculated according to the average linear deviation of economic benefits from the housing purchasing; the estimated market value of a residential real estate object is calculated taking into account the risk factor; the profitability index of the particular dwelling purchase operation is calculated. The practical implication of the developed methodological principles of the risk planning in housing construction investing in the practice of the construction subjects will increase the approved management decisions validity.

Application of a Reduced Order Model for Fuzzy Analysis of Linear Static Systems

Abstract This contribution proposes a strategy for performing fuzzy analysis of linear static systems applying α-level optimization. In order to decrease numerical costs, full system analyses are replaced by a reduced order model that projects the equilibrium equations to a small-dimensional space. The basis associated with the reduced order model is constructed by means of a single analysis of the system plus a sensitivity analysis. This reduced basis is enriched as the α-level optimization strategy progresses in order to protect the quality of the approximations provided by the reduced order model. A numerical example shows that with the proposed strategy, it is possible to produce an accurate estimate of the membership function of the response of the system with a limited number of full system analyses.

A computational model for complex systems analysis: Causality estimation

Analysis of complex systems has migrated from theoretical analysis of model physical systems into the domain of real-world applications with far-reaching implications. This shift has been facilitated by the availability of measurement data, the capability to store and manage large-scale datasets, and significant increase in computational power. These developments have been matched by a concerted effort in the development of new methods of complex systems analysis. Each class of analytical methods are applicable only for certain system types and specific problems, such as estimating causality between coupled complex systems, are still unresolved even for simples cases involving only two connected systems. This study summarizes results for estimating causality using a novel mathematical computational model, System Structure, across several different types of coupled systems. System structure models a system as a dynamic network of connected components and provides a distribution-free and systematic quantification of inter-component dynamics as a basis for making several system-wide inferences including the inference of strength and direction of causal relations. System structure is a non-parametric scalable method that requires few non-restrictive a-priori assumptions, making it generally applicable across a diverse set of problems. The comparative study reported on here demonstrates the ability of system structure to correctly infer different types of causality across diverse system types.

Small-Signal Stability Analysis for Power System Frequency Regulation with Renewable Energy Participation

With the improvement of the permeability of wind and photovoltaic (PV) energy, it has become one of the key problems to maintain the small-signal stability of the power system. Therefore, this paper analyzes the small-signal stability in a power system integrated with wind and solar energy. First, a mathematical model for small-signal stability analysis of power systems including the wind farm and PV station is established. And the characteristic roots of the New England power system integrated with wind energy and PV energy are obtained to study their small-signal stability. In addition, the validity of the theory is verified by the voltage drop of different nodes, which proves that power system integrated with wind-solar renewable energy participating in the frequency regulation can restore the system to the rated frequency in the shortest time and, at the same time, can enhance the robustness of each unit.

Modeling and Simulation of Power Quality for EAST

To ensure the safety and efficiency of EAST nuclear fusion devices, the power quality has to be considered. The loads of EAST device are complex and diverse, especially the special loads with high power impact, volatility, randomness and nonlinear characteristic, which causes power quality problems such as voltage sag, harmonic and three-phase imbalance in power network. This paper analyzes the load characteristics of EAST devices and divides them into impulsive loads and conventional loads. The above two types of loads are modeled and simulated respectively, and the effects of loads with different properties on the system are discussed. The results of simulation analysis are of great significance to the next step of formulating corresponding compensation measures and developing control equipment. Therefore, the importance of power quality problems modeling and simulation for power system analysis and control is self-evident.

Improvement of management systems for the transportation process at the test site of the Northern Railway

The relevance of the study is determined by the fact that today at the test site of the Northern Railway, client-oriented priorities are being actively implemented and measures are being taken to attract new customers to the network, which will increase the share of highly profitable cargo and loading volumes in general, as well as the volume of cargo operations at stations.An attempt was made to propose a change in technology and increase the throughput on the Solombalka – Karpogory section from five to ten pairs of trains per day, based on an assessment of the prospective volumes of work associated with the development of stations in the region and the operating costs associated with their operation.The current state of cargo and commercial operations in the Arkhangelsk region of the Northern Railway was considered, and the prospects for the development of cargo operations were identified.The subject of research is loading stations. The object of the study is the Arkhangelsk territorial administration of the Northern Railway — a branch of JSC Russian Railways.Methods of system analysis, observation method, statistical method, forecasting and predictive modeling are applied.A feasibility study for changing technology and increasing throughput on the Arkhangelsk city – Karpogory section has been carried out. The economic efficiency of the proposal has been confirmed. The research carried out is the result of a two-year interaction with the Northern Railway. The research elements have already been introduced at the Northern Railway test site.