ВИЗНАЧЕННЯ ЦІЛЬОВОЇ ФУНКЦІЇ ОПТИМІЗАЦІЇ ВТРАТ СТО, ПОВ’ЯЗАНИХ З ТИПОМ ОРГАНІЗАЦІЇ ПРИЙМАННЯ-ДІАГНОСТУВАННЯ АВТОМОБІЛІВ

Reliability analysis of M/G/1 queueing system with repairable service station of reliability series structure

A tandem retrial queueing system with two Markovian flows and reservation of channels

This paper studies the optimal operation of an M/Ek/1 queueing system with a removable service station under steady-state conditions. Analytic closed-form solutions of the controllable M/Ek/1 queueing system are derived. This is a generalization of the controllable M/M/1, the ordinary M/Ek/1, and the ordinary M/M/1 queueing systems in the literature. We prove that the probability that the service station is busy in the steady-state is equal to the traffic intensity. Following the construction of the expected cost function per unit time, we determine the optimal operating policy at minimum cost.

Formulations of structured dairy products that demonstrate good organoleptic properties are considered the most promising in terms of meeting consumer demands, increasing market share, and enhancing the competitiveness of domestic dairy production. The selection of dairy bases (low-fat curd, pumpkin cryopowder, and cream), which possess diverse structural-mechanical characteristics and functional-technological properties, is scientifically justified and aimed at developing a range of structured dairy products containing functional food components. Viscosity was chosen as the target function for optimization, as it is a key indicator characterizing the consistency and structure of viscous products, such as the curd-based product being developed. An analysis of the response surface revealed that the optimal viscosity zone for the curd product is achieved when the mass fraction of curd is 89.6%, the mass fraction of cryopowder is 5.4%, and the fat content in the cream is 31.3%. The characteristic viscosity for curd products ranges from 1400 to 2500 mPa·s. The analysis of prediction error distribution for viscosity values yielded satisfactory results: a significant portion of the data points remained close to the trendline, confirming the adequacy of the model. This indicates the formation of a product structure in which the fermented protein coagulate plays a key role. Therefore, the viscosity, consistency, and consumer properties of the final product largely depend on its concentration.

A finite-buffer single-channel queueing model with batch Poisson arrivals and generally-distributed processing times is considered, in which a variant of a vacation policy is implemented. Namely, every time when the service station becomes idle, a number of constant vacation times are being initialized repeatedly, until at least one packet will income into the accumulating buffer. During the whole vacation period the processing of packets is suspended. Applying the analytical method based on the idea of embedded Markov chain and linear-algebraic approach, a compact-form representation for the Laplace transform of the queueing delay tail distribution is found. The considered queueing system can be utilized in performance evaluation of wireless network nodes with energy saving mechanism based on constant repeated vacations.

Customers arriving randomly are served by a queueing system consisting of a sequence of two service stations with infinite queue allowable before the first station and no queue allowable between the stations. The moment generating functions of the steady-state queueing times as well as the generating functions of the steady-state numbers of customers in the various parts of the system are obtained under assumptions of Poisson process of arrivals and arbitrarily distributed service times at both stations. The cases of regular and exponential service times are investigated in some more detail, and the results obtained are extended to include the queueing system with a sequence of two stations with a finite intermediate queue allowable between them, infinite queue allowed before the first station, Poisson process of arrivals and regular service times at both stations.

This article proposes a jitter-aware decoupling capacitors placement optimization method that uses the genetic algorithm (GA). A novel method for defining the optimization target function in regard to power delivery network (PDN) and power source-induced jitter (PSIJ) optimization based on the GA-based tool is proposed. The proposed method can provide an optimum and economic solution for the number of decoupling capacitors to use in a PDN to reach the target impedance. Then, by modifying the optimization target function with our proposed method, an optimum solution of the number of decoupling capacitors regarding the PSIJ can be obtained. The PSIJ analytical expressions are derived in conjunction with a resonant cavity model that includes the coordinates of the decoupling capacitors and the PSIJ transfer function. The GA-based optimization algorithm with the proposed target function is first applied to optimize the number of decoupling capacitors regarding the PSIJ. Finally, the measured jitters from HSPICE simulation results are used to verify our optimization method such that both the simulated results and analytically calculated results support the efficiency of our proposed optimization method.

In cognitive radios, the first and crucial task is to detect the spectrum holes or the presence of primary user by employing spectrum sensing. However, there exist two kinds of detection errors (i.e., miss-detection error and false-alarm error), which degrade the sensing performance severely. Aiming at minimizing the probability of total detection errors, based on the law of total probability we propose a novel target function (which also denotes the so-called comprehensive sensing performance metric) for optimization of sensing parameters. According to such established target function, we then apply the method of extremum seeking to develop the optimization of time-bandwidth product and sensing threshold jointly for local spectrum sensing with energy detection. Moreover, we further derive the closedform expression of the optimal fusion rule for cooperative spectrum sensing by performing the discrete difference operation on the target function. Finally, the optimal area of joint parameters selection for local spectrum sensing and the effect of different detecting channel conditions on the optimization for cooperative spectrum sensing are evaluated numerically.

In modern methods of technological design, the capacity of service facilities depends on the number of cars entering them per unit of time. At the same time, regardless of the type of service object, the number of visits is somehow associated with intensity of the vehicle traffic on a given road, as well as with one of the characteristics that determine speed of this event. Such a characteristic, for example, for service or maintenance stations is intensity of vehicle failures, for fuelling stations – intensity of fuel consumption, for hotels and parking lots – intensity of the onset of fatigue for drivers and passengers. This gives ground for conclusion that there is a significant similarity between the processes that result in an event that can be called a visit to a service facility. Thus, the purpose of this theoretical study was to develop a common approach applicable to all road service facilities to determine the number of such events, as well as to develop a common methodology for their design.A characteristic feature of operation of service objects is a time-varying flow of demand for the operation of service facilities, as well as variable labour intensity and duration of troubleshooting or the provision of other service services. Systems in which the moments of receipt of requests for service and the duration of the services themselves are variable and random are called a queuing system. Therefore, to justify the number of car arrivals at road service facilities, the authors proposed a probabilistic method, the main tools of which are provisions and mathematical apparatus of the queuing theory.The main condition for functioning of the queuing system is the ratio between the incoming flow of requirements and the absolute throughput of the system. Thus, the mathematical model proposed by the authors considers the performance indicators of service facilities, depending on the size of the incoming flow of requirements and its variation, on the one hand, and on the throughput and performance of service facilities, on the other hand.

In this paper, we develop a multi-objective model to optimally control the lead time of a manufacturing system, using goal attainment method. The manufacturing system is modelled as a new queueing system based on the failure rate of products, in which the products may have quality problems and need to be repaired in each service station. It is assumed that the product order arrives according to a Poisson process. In each service station, there is only one server (machines) with exponentially distributed processing time, in which the service rate (capacity) is controllable. The maintenance time of manufacturing and assembly operations is exponentially distributed. By using the total probability decomposition and Markov process method, the Queue Length Distribution, the recursion expression of the equilibrium distribution and the mean waiting time are obtained. Then, we develop a multi-objective optimal control problem, in which the average lead time, the maintenance costs and the operating costs of the system per period are minimized using goal attainment method.

Introduction. As part of the implementation of the Order of the Government of the Russian Federation dated August 29, 2025, No. 2366-r, there is an active development of gas-powered transport. In order to improve the level of fire safety at such facilities, it is proposed to use continuous monitoring systems for the gas-air environment. Aims and Purposes. The purpose of the study is to conduct a comprehensive analysis of various regulatory documents in the field of fire safety applied to buildings with the presence of gas-cylinder automotive equipment, to process the obtained statistical data, and to supplement the method used in calculating fire risk to assess the frequency of fires at facilities for servicing vehicles using gas-powered fuel. To develop a method for improving fire safety, taking into account the possible placement of devices for detecting combustible gases at various facilities. Research methods. To solve the set tasks, field tests were conducted at a specialized test site in Orenburg to study the concentration fields of combustible gas in an enclosed space. The data obtained were systematized and allowed for the development of proposals to improve the fire safety of facilities with GCE systems by monitoring the state of the gas-air environment. Results and Discussion. Statistical data was analyzed to assess the frequency of fires. The calculation was based on the total number of vehicles in Russia, the proportion of cars with GCE systems, and the number of registered fire incidents. The results were systematized and studied in detail. Using the statistical data obtained and the proposed method for determining frequency, coefficients “a” and “b” were obtained. Conclusion. Based on the data obtained, as well as taking into account the conducted analytics and experimental studies, a method has been proposed to improve the level of fire safety at service stations with GPT by taking into account the presence of gas analyzers at these facilities. The proposed methodology, based on the possibility of accounting for devices for detecting gas contamination in various facilities with the presence of gas-cylinder equipment, will help reduce the likelihood of emergencies and improve existing calculation methods.

The location of Low-Altitude Flight Service Station (LAFSS) is a comprehensive decision work, and it is also a multi-objective optimization problem (MOOP) with constraints. As a swarm intelligence search algorithm for solving constrained MOOP, the Immune Algorithm (IA) retains the excellent characteristics of genetic algorithm. Using some characteristic information or knowledge of the problem selectively and purposefully, the degradation phenomenon in the optimization process can be suppressed and the global optimum can be achieved. However, due to the large range involved in the low-altitude transition flight, the geographical characteristics, economic level and service requirements among the candidate stations in the corridor are quite different, and the operational safety and service efficiency are interrelated and conflict with each other. And all objectives cannot be optimal. Therefore, this article proposes a Modified Immune Algorithm (MIA) with two-layer response to solve the constrained multi-objective location mathematical model of LAFSS. The first layer uses the demand track as the cell membrane positioning pattern recognition service response distance to trigger the innate immunity to achieve the basic requirements of security service coverage. In the second layer, the expansion and upgrading of adjacent candidate sites are compared to the pathogen’s effector, and the adaptive immunity is directly or indirectly triggered again through the cloning, mutation and reproduction between candidate sites to realize the multi-objective equilibrium of the scheme. Taking 486,000 km2 of Sichuan Province as an example, MIA for LAFSS is simulated by the MATLAB platform. Based on the Spring open source application framework of Java platform, the cesiumjs map data is called through easyui, and the visualization of site selection scheme is presented with the terrain data of Map World as the background. The experimental results show that, compared with dynamic programming and ordinary immunization, the immune trigger mode of double response and the improved algorithm of operation parameter combination designed by the Taguchi experiment, the total economic cost of location selection is reduced by 26.4%, the service response time is reduced by 25%, the repeat coverage rate is reduced by 29.5% and the effective service area is increased by 17.5%. The security risk, service efficiency and location cost are balanced. The present work is to provide an effective location method for the layout number and location of local transfer flight service stations. For complex scenes with larger scale of low-altitude flight supply and demand and larger terrain changes in the region, the above research methods can be used to effectively split and reduce the dimension.

This study aims to evaluate the service infrastructure of Ketapang Railway Station based on users and public interest. The research method used was a survey method by distributing questionnaires to Ketapang railway station users and potential users of the station. The questionnaire included questions about the quality of station services, user expectations and needs, as well as public interest in railway station services. The results of the study showed that the infrastructure facilities at Ketapang railway station had met the minimum standard service regulations in place. From the analysis of the customer satisfaction index, it was found that the criteria for "very satisfied" was achieved with a score of 90.38%. In addition, the public interest in Ketapang railway station services was very high. These recommendations are expected to help improve the quality of Ketapang railway station services and increase public interest in using the station's services.

Using Fruit Fly Optimization Algorithm (FOA) to optimize the Proportion Integration (PI) control parameters of the single-phase inverter. The transfer function model of the single-phase inverter is obtained by the state space averaging method, and the globally optimum solution to parameters of the PI controller has been searched by using FOA with total harmonic distortion (THD), gain margin and phase margin of the system open-loop function as optimal target functions. Compared with the initial system, the optimal target function marks optimized system has a better control stability; also, the waveform of its output voltage has a smaller THD. According to the Matrix Laboratory (MATLAB) simulation result, it shows that FOA possesses faster convergence speed than Particle Swarm Optimization (PSO), and FOA can effectively find out the globally optimum solution. Upon applying the optimized PI controller to a single-phase inverter, the system has a good stability with a small THD of the output voltage waveform. Thus, the feasibility and effectiveness of applying FOA to the control optimization of the power electronics system can be proven.

To mitigate the frequency stability challenges induced by random power fluctuations and alterations in Load Frequency Control (LFC) parameters during large-scale wind power integration, an optimal PID controller design method based on an intelligent optimization algorithm is presented in this paper. Firstly, a PID-controlled closed-loop LFC model for interconnected power systems incorporating wind generation is established by using static output feedback control method. Secondly, the minimum value of the integral of time multiplied absolute error (ITAE) index of the time - domain output response is selected as the optimization target function, and the optimal PID controller settings are obtained by using the sine cosine algorithm (SCA) with excellent performance. Finally, simulation results confirm that the suggested LFC method has remarkable robustness, even under condions of step load and random load disturbances, wind power deviation effects, and system parameter variations. Additionally, it facilitates greater wind power penetration into the grid.