Operation Algorithm Research Articles

Emergency Prevention Control as a Means of Power Quality Improvement in a Shipboard Hybrid Electric Power System

The problems associated with the greenhouse effect have increased the desire to limit carbon dioxide (CO2) emissions into the atmosphere, including emissions produced by shipboard electrical power systems. This has led to a further search for solutions in this area, such as shipboard hybrid electric power systems (SHEPSs). These systems do not yet have a wide application compared with traditional shipboard electrical power systems for several reasons, including the lack of studies establishing the fault tolerance of such systems. Therefore, in this work, problems related to generated power quality deterioration under large disturbances are studied. To achieve the fault-free operation of SHEPS, an emergency prevention control (EPC) system based on controlled parameter forecasting, along with a system structure and operation algorithm, is developed. The goals of improving electrical power quality are achieved by increasing the control efficiency of the power system’s generating sources. To validate the feasibility of the proposed control system, a computer simulation was carried out after developing a mathematical model of the SHEPS under study. The results of the study show that the use of the proposed EPC system will improve power quality when the controlled parameters are within acceptable limits. At the same time, further research is needed, as the problem of false control action as a consequence of EPC system hardware or software faults remains unstudied.

Realization of ultracapacitor as sole energy storage device in induction motor drive electric vehicle with modified state timing based field weakening control algorithm

This article employs the concept of realizing an electric vehicle (EV) driven by an induction motor (IM) with an ultracapacitor (UC) as a sole energy storage device for a short distance range in city drive. In battery-driven EVs, the performance of batteries will extensively degrade during frequent start, stop, acceleration and deceleration of the vehicle. However, UC can withstand that circumstance without any degradation. High charge/discharge efficiency, high power density, high temperature withstand capabilities and quick charging capability allows UC to run the EV for an extended range, including the regenerative braking technique. Apart from source, EVs also require efficient drive control for a smooth vehicle operation in the entire driving range. To achieve the vehicle characteristics, it is preferred to operate the propulsion drive in the field weakening (FW) region over the constant torque region. This paper also proposes a Modified State Timing SVPWM Based Control Algorithm for the FW region operation of IM for EV applications. The proposed algorithm is designed to overcome the torque ripple issue of the conventional SVPWM Based Control Algorithm in the FW region. The reduction in torque ripple is achieved by imposing current and voltage limits on the motor d and q axis by considering a maximum modulation index of 1.2732 and with an additional current loop for mitigating the transients in the torque due to sudden variation of the load. The simulation/hardware studies show a smooth operation of UC-driven EV for an entire driving range with a 78.57 percent improvement in torque ripple in the FW region by the proposed algorithm compared with the conventional FW control algorithm. The real time Lab prototype of UC driven EV has been developed and the proposed algorithm has been validated in real-time using the STM32F407VGTx ARM Cortex M4 microcontroller.

A New Link Adaptation Technique for Very High Frequency Data Exchange System in Future Maritime Communication

The growing demand for communication technology capable of providing high transmission rates in maritime environments has led to the exploration of the very high frequency (VHF) data exchange system (VDES) as a promising solution. The VDES, the integration of an automatic identification system (AIS), application-specific messaging (ASM), and VHF data exchange (VDE), offers improved transmission rates and stable connections compared with existing technologies. Although the VDES supports high transmission rates through various modulation and coding scheme (MCS) technologies, it lacks a standardized mechanism for controlling MCS parameters and relies on user algorithms for operation. In this paper, we introduce the maritime auto-rate fall-back (mARF) technology, designed to effectively address the challenges of maritime communication scenarios using the MCS framework provided by the VDES. mARF technology incorporates fast drop-out and recovery mechanisms to swiftly adapt to changing MCS types in the presence of deep nulls, a common occurrence in maritime communication environments. These adaptive thresholds for fast drop-out and recovery operations are dynamically learned using historical communication data. Through extensive simulations, we demonstrate the effectiveness of mARF in enhancing the MCS control capabilities of the VDES. Our results show a significant performance improvement of 18% compared to the existing model, validating the potential of mARF in optimizing maritime communication channels and supporting a high transmission rate.

Practical and privacy-preserving geo-social-based POI recommendation

With the rapid development of location-based services and online social networks, POI recommendation services considering geographic and social factors have received extensive attention. Meanwhile, the vigorous development of cloud computing has prompted service providers to outsource data to the cloud to provide POI recommendation services. However, there is a degree of distrust of the cloud by service providers. To protect digital assets, service providers encrypt data before outsourcing it. However, encryption reduces data availability, making it more challenging to provide POI recommendation services in outsourcing scenarios. Some privacy-preserving schemes for geo-social-based POI recommendation have been presented, but they have some limitations in supporting group query, considering both geographic and social factors, and query accuracy, making these schemes impractical. To solve this issue, we propose two practical and privacy-preserving geo-social-based POI recommendation schemes for single user and group users, which are named GSPR-S and GSPR-G. Specifically, we first utilize the quad tree to organize geographic data and the MinHash method to index social data. Then, we apply BGV fully homomorphic encryption to design some private algorithms, including a private max/min operation algorithm, a private rectangular set operation algorithm, and a private rectangular overlapping detection algorithm. After that, we use these algorithms as building blocks in our schemes for efficiency improvement. According to security analysis, our schemes are proven to be secure against the honest-but-curious cloud servers, and experimental results show that our schemes have good performance.

Collaborative algorithm of workpiece scheduling and AGV operation in flexible workshop

PurposeThis study aims to solve the problem of job scheduling and multi automated guided vehicle (AGV) cooperation in intelligent manufacturing workshops.Design/methodology/approachIn this study, an algorithm for job scheduling and cooperative work of multiple AGVs is designed. In the first part, with the goal of minimizing the total processing time and the total power consumption, the niche multi-objective evolutionary algorithm is used to determine the processing task arrangement on different machines. In the second part, AGV is called to transport workpieces, and an improved ant colony algorithm is used to generate the initial path of AGV. In the third part, to avoid path conflicts between running AGVs, the authors propose a simple priority-based waiting strategy to avoid collisions.FindingsThe experiment shows that the solution can effectively deal with job scheduling and multiple AGV operation problems in the workshop.Originality/valueIn this paper, a collaborative work algorithm is proposed, which combines the job scheduling and AGV running problem to make the research results adapt to the real job environment in the workshop.

A modified two-archive evolutionary algorithm for many-objective ecological cascade reservoir operation

A modified two-archive evolutionary algorithm for many-objective ecological cascade reservoir operation

Microelectronic device for control of rail line integrity in Uzbekistan

The paper presents the results of theoretical research on the organization of the construction of a device for monitoring the condition of rail lines on railway sections equipped with rail chains without insulated joints. The analysis of the possible reasons for the lack of rail line integrity and its possible consequences is carried out. The functional scheme of the device with the use of a microcontroller is proposed, the software of which carries out a continuous analysis of the ratio of the values of two induced electromotive forces, the results of calculations are formalized in the form of a data package and transmitted to the station. The model based on graph theory is developed and studied, the algorithm of the device operation is given.

Power Loss Reductions and Voltage profile improvement through Fuzzy and AO algorithm for effective system operation by optimal placement of UPFC

Power Loss Reductions and Voltage profile improvement through Fuzzy and AO algorithm for effective system operation by optimal placement of UPFC

Modified Arithmetic Algorithms for Optimal Power System Operation Considering Uncertainties from Intermittent Renewable Energy and Electric Vehicles

Modified Arithmetic Algorithms for Optimal Power System Operation Considering Uncertainties from Intermittent Renewable Energy and Electric Vehicles

Автоматическая система позиционирования колёсных роботизированных технических средств, обслуживающих кормовой стол

The quality and availability of forage on the feed table increase cow productivity. Feed availability can be ensured by increasing the length of the feed table and using robotic tools. The use of a wheeled robotized device in feed distribution increases labour productivity and reduces the influence of the human factor on the feeding process. To improve the efficiency of the feed distribution process, the author has developed and tested an automatic positioning system and a robotic device for servicing the feed table. The article presents a mathematical description of the kinematic relationships of movement of wheeled robotic devices. The author has developed an algorithm of the automatic positioning system operation, which takes into account the algorithmic connection between the electric drive actuators of the driving wheels and the vision system, where the image is processed according to the intellectual algorithm of the feeding area recognition. The author has developed the principle of constructing the route travelled by the robotic device along the feed table. Tests have confirmed the conformity of output reactions of the robotic device actuators to the input commands of the automatic positioning system.

Efficient Algorithm for All-Gather Operation in Optical Interconnect Systems

Efficient Algorithm for All-Gather Operation in Optical Interconnect Systems

Fuzzy Superposition Operation and Knowledge-driven Co-evolutionary Algorithm for Integrated Production Scheduling and Vehicle Routing Problem with Soft Time Windows and Fuzzy Travel Times

Fuzzy Superposition Operation and Knowledge-driven Co-evolutionary Algorithm for Integrated Production Scheduling and Vehicle Routing Problem with Soft Time Windows and Fuzzy Travel Times

УПРАВЛЕНИЕ ОРГАНИЗАЦИЕЙ В ЭПОХУ ЦИФРОВОЙ ТРАНСФОРМАЦИИ

This paper analyzes the implementation of digital transformation in the management of an organization. The directions of digital transformation and approaches to its implementation are defined, indicating the general algorithm of operation of this tool to increase the competitiveness of the enterprise. The external and internal risks of the organization in the process of digitalization are highlighted. The KPI system has been identified as a method for evaluating the effectiveness of digitalization in an enterprise.

Development of a simulation model for controlling energy storage systems on electric trains

The article discusses the experience of using electrical energy storage devices on multiple unit rolling stock, both in Russia and abroad. It is noted that the use of energy storage systems in railway transport in Russia lags somewhat behind its foreign colleagues. The main assumptions taken when performing simulation modeling of the operation of energy storage systems on an electric train are presented. Simulations of the operation of energy storage systems were carried out using the MatLab software package. Simulation models of an electric train with an energy storage device, a model of a heater for heating an electric train car, a model of a hybrid energy storage system, a model of a supercapacitor unit, and batteries are presented. The algorithm of operation of the active topology of a hybrid drive is considered. The developed simulation models have been tested. Graphs of the voltage at the pantograph and the current consumed by the electric train were obtained, as well as graphs of the operation of the battery and supercapacitor in charge/discharge modes.

The operation model of the point setting relay for a microelectronic device

The application of electromagnetic relays in train control systems in rail transport is a challenging task. The solution of this innovative problem is based on the use of microelectronic, contactless elements, graph theory, process modeling, and the use of microprocessors. A Petri net multigraph has been developed and investigated for various operating modes of route cutting relays. Multigraphs, the functional diagram, and the algorithm of operation of the microelectronic relay block are given.

Функционирование системы управления рисками и внутреннего контроля на производственном предприятии

The implementation of digital technologies and the rapid transition to Industry 4.0 have influenced the speed of information exchange, thereby increasing uncertainty and the likelihood of making ineffective management decisions. At the same time, to avoid entropy in managing a manufacturing enterprise, a transformation of tools, methodologies, procedures, and standards is necessary to ensure the company’s sustainable development. One way to increase the reliability of a company’s operations in conditions of uncertainty and risk can be the organization of a risk management and internal control system (RMIC). RMIC is defined as a set of organizational measures, methodologies, procedures, norms of corporate culture and actions aimed at achieving an optimal balance between value growth, profitability, and risks to ensure financial stability, efficient business operations, asset preservation, compliance with laws, statutes, and internal documents, timely preparation of accurate reports. Furthermore, in uncertain conditions, it is advisable to consider RMIC in the context of an integrated business-process system because, to ensure reasonable confidence in achieving the company’s goals in operational activities, reporting, and fulfilling all obligations, it implies organizing risk management primarily at the process and operational (transactional) levels, and aims at increasing the efficiency of the company’s activities as a result of integrating risk management with strategic planning processes, business planning, and decision-making. The article presents the conceptual foundations of a production enterprise’s RMIC. Key performance indicators, internal control procedures, key risk indicators, the structure of elements and system operation algorithms are justified. Theoretical conclusions of the authors are based on the results obtained within the framework of testing the proposed RMIC model for the business process “Construction Supervision Organization for Gazprom Customers”. It is concluded that, to ensure confidence in achieving goals at a production enterprise, RMIC should be developed, implemented, and continuously developed. Risk management and internal control processes should be carried out using best practices, principles, and methods. In this case, the risk management measures taken by the company will allow risks to be kept within acceptable limits and provide shareholders with sufficient guarantees to achieve their goals and objectives.

Scientific and Engineering Proposals for Improving the Noise Immunity of Receiving Multi-Position Signals in Channels with Variable Parameters

Introduction. An important task faced by the developers of modern telecommunication systems consists in increasing the noise immunity of signal reception in channels with variable parameters. Thus, the communication lines of DVB-T2, DVB-S, and DVB-S2/S2 standards widely apply signal structures (SS) of multi-position quadrature amplitude modulation (M-QAM). However, an analysis of scientific publications shows that the random nature of the phase change of the transformed signal constellation leads to a loss of noise immunity of the M-QAM signals. Engineering solutions for the effective reception of such signals are lacking. The proposed block diagram of a device for receiving quadrature amplitude signals and the developed operation algorithm for an amplitude-phase detector allow random phase changes to be considered and reduced.Aim. Development of scientific and engineering proposals to improve the efficiency of receiving M-QAM signals in radio channels with random phase changes.Materials and methods. The study was conducted using the methods of noise immunity research, as well as communication theory and signal theory.Results. A block diagram of a device for receiving quadrature amplitude signals and an operation algorithm for an amplitude-phase detector were proposed, which allow random phase changes to be considered and compensated for. Scientific and engineering proposals were formulated to improve the noise immunity of M-QAM reception in channels with variable parameters.Conclusion. The developed scientific and engineering proposals for increasing the noise immunity of multi-position quadrature signals in channels with variable parameters substantiate both the feasibility of using a transformed SS M-QAM with improved energy characteristics, as well as the application of the developed receiving device for processing quadrature amplitude signals and the operation algorithm of an amplitude-phase detector. The results obtained make it possible to perform demodulation with simultaneous compensation of phase distortions to increase the noise immunity of M-QAM signal reception.

Application of Methods of Recommendations in the Analysis of Computer Components

Today, the improvement of information and technical assistance to users through information technology is relevant. To improve the design of computers, we analyze its components and study the architecture, as well as the process of improving the functionality of a computer. We conducted an analytical review of existing software solutions for analyzing computer components. We consider models for forming a set of recommendations taking into account the wishes of the user. Given the specifics of the analysis of the problem situation, it is proposed to unite users into groups. Mixed categorical-numerical clustering was used to search for user groups. This took into account the numerical (Item ratings) and demographic properties of users, as well as the sparsity coefficient of the User-Item Matrix. His algorithm of operation of the hybrid recommendation system is described, which proposes to take into account the user's requirements when analyzing and generating component variability for a computer, a hybrid model of providing recommendations with a weighted weight factor is used. UML provides a conceptual model of the system. The recommendation system allows the user to use computer analysis of components, which will offer the best components and, most importantly, the most suitable details. If the user wants a completely new computer, he can use the assembly designer. Components will be selected for the user request, or a part of the computer will be offered. The target audience of the program is PC users of any age.

CROSS-PLATFORM SOFTWARE SYSTEM FOR THE LOGISTICS OF HUMANITARIAN SERVICES

The problem of designing a cross-platform software system for the logistics of humanitarian services is considered. Existing software analogs of international deliveries are considered. A comparison of popular software products in the field of international trade is given. The technologies for developing software services to ensure the cross-platform system for the logistics of humanitarian services are reviewed. The algorithms used in the system for solving the transportation problem, namely the routing problem, are presented, with the help of which the most optimal path between the supply points is selected. The general algorithm of the system operation is proposed and the structural diagram of the application is presented. Keywords: cross-platform, software service, logistics, algorithm, application.

GPPM: A Generalized Matrix Operation and Parallel Algorithm to Accelerate the Encoding/Decoding Process of Erasure Codes

Erasure codes are widely deployed in modern storage systems, leading to frequent usage of their encoding/decoding operations. The encoding/decoding process for erasure codes is generally carried out using the parity-check matrix approach. However, this approach is serial and computationally expensive, mainly due to dealing with matrix operations, which results in low encoding/decoding performance. These drawbacks are particularly evident for newer erasure codes, including SD and LRC codes. To address these limitations, this article introduces the Partitioned and Parallel Matrix ( PPM ) algorithm. This algorithm partitions the parity-check matrix, parallelizes encoding/decoding operations, and optimizes calculation sequence to facilitate fast encoding/decoding of these codes. Furthermore, we present a generalized PPM ( gPPM ) algorithm that surpasses PPM in performance by employing fine-grained dynamic matrix calculation sequence selection. Unlike PPM, gPPM is also applicable to erasure codes such as RS code. Experimental results demonstrate that PPM improves the encoding/decoding speed of SD and LRC codes by up to 210.81%. Besides, gPPM achieves up to 102.41% improvement over PPM and 32.25% improvement over RS regarding encoding/decoding speed.