Operational Control Research Articles

Research on a Plan of Free Cooling Operation Control for the Efficiency Improvement of a Water-Side Economizer

Research on a Plan of Free Cooling Operation Control for the Efficiency Improvement of a Water-Side Economizer

A Bibliometric Analysis of Supply Chain Management within Modular Integrated Construction in Complex Project Management

As construction projects become increasingly complex, modular integrated construction (MiC) has emerged as a pivotal solution, driving integrated development in complex projects. However, the reliance on prefabricated modules underscores the crucial role of supply chain management (SCM) in MiC, necessitating strategic planning and operational control. This study aimed to use bibliometric analysis to map the SCM knowledge domain within MiC. Through the use of keywords related to “supply chain” and “MiC”, 196 relevant papers were extracted from the Web of Science database. These papers were subjected to co-citation analysis, keyword co-occurrence analysis, and time span analysis to elucidate the historical evolution, multidisciplinary domains, and future directions in planning and control within SCM-MiC. The research identified two milestones in SCM-MiC’s historical trajectory, enhancing our understanding of its foundations. Moreover, 11 clusters were identified, illustrating the multidisciplinary nature of SCM-MiC. Dividing the literature into seven stages of the supply chain, the research outlined four research directions aligned with project complexity and technological development, highlighting current hotspots and gaps of the strategic planning and control. These directions bridge the construction management and information technology domains, guiding future SCM-MiC research within complex project management.

Monitoring Equipment Malfunctions in Composite Material Machining: Acoustic Emission-Based Approach for Abrasive Waterjet Cutting

This paper introduces an Acoustic Emission (AE)-based monitoring method designed for supervising the Abrasive Waterjet Cutting (AWJC) process, with a specific focus on the precision cutting of Carbon Fiber-Reinforced Polymer (CFRP). In industries dealing with complex CFRP components, like the aerospace, automotive, or medical sectors, preventing cutting system malfunctions is very important. This proposed monitoring method addresses issues such as reductions or interruptions in the abrasive flow rate, the clogging of the cutting head with abrasive particles, the wear of cutting system components, and drops in the water pressure. Mathematical regression models were developed to predict the root mean square of the AE signal. The signal characteristics are determined, considering key cutting parameters like the water pressure, abrasive mass flow rate, feed rate, and material thickness. Monitoring is conducted at both the cutting head and on the CFRP workpiece. The efficacy of the proposed monitoring method was validated through experimental tests, confirming its utility in maintaining precision and operational integrity in AWJC processes applied to CFRP materials. Integrating the proposed monitoring technique within the framework of digitalization and Industry 4.0/5.0 establishes the basis for advanced technologies such as Sensor Integration, Data Analytics and AI, Digital Twin Technology, Cloud and Edge Computing, MES and ERP Integration, and Human-Machine Interface. This integration enhances operational efficiency, quality control, and predictive maintenance in the AWJC process.

Evaluation of Productivity and Cost Analysis on a Combined Logging System

The efficient planning and control of timber harvesting operations is crucial to growth productivity and reducing costs, and different systems or methods are applied to obtain elevated performance. In particular, cable yarding is a highly appreciated and very efficient wood extraction method in areas that are difficult to access with ground-based extraction machines. Combined logging systems are not diffuse and not often implemented. For this reason, the use and the application of innovative methods are limited. However, some combinations have recently been observed in forest operations. This study, conducted in a deciduous stand in Bulgaria, paid attention to the combination of a tractor-mounted tower yarder (Valentini V400) with a clambunk skidder (Timberjack 1010D), aiming to examine the viability and develop the operational efficiency of the two-stage extraction system and to define the time, log volume extracted per unit by the yarder and the clambunk, and the yarding and skidding costs. The researchers carried out a time-motion study and performed a regression analysis to identify those variables that are most likely to affect the duration of work elements and productivity. For cost analysis, the COST model was used. The mean productivity of the tower yarder was 10.34 m3/PMH and 8.11 m3/SMH, while for the clambunk skidder, the productivity was 6.23 m3/PMH and 4.93 m3/SMH. The net costs for the combined logging system were calculated as 120.87 €/PMH and 14.93 €/m3. This study adds new data about the correct use of both machines, supporting their application in beech forests.

Design and Simulations of Solar-Based Hydrogen Production System via Methane Decomposition

A solar-based hydrogen production system is analyzed and studied with the intention of optimizing the parameters involved in oil refining industry and the environment of the United Arab Emirates. Methane decomposition in molten salt media using a concentrated solar power system was adopted, since the temperature range required in the system design is achievable with this method. The System Advisor Model software was used in this study with three cases to optimize the system using the levelized cost of heat concept. In Case 1, a levelized cost of heat of 9.32 ¢/kWh was achieved using an optimized system with a CSP-RTUVR-2014 receiver and a Luz LS-3 collector. The design of Cases 1 and 2 exhibited pressure drops along the system of just 10 bar, significantly lower than the 50 bar of Case 3. Similarly, designs of Cases 1 and 2 resulted in maximum receiver thermal losses of around 7 MW, whereas Case 3 yielded 14 MW loss. Analysis of the best-suited molten salt option showed that HITEC solar salt was better than HITEC XL and standard HITEC. A regression analysis was carried out to examine the pressure drop responses since it is a key variable affecting the integrity of the solar system. It was observed that the receiver mass flow rate is the main contributing cause of pressure drop. Through careful operator control of receiver mass flow rate, premature failures of the solar system caused by the pressure drop can be avoided.

Optimized Design and Operation Control of Refrigerant Direct Cooling Thermal Management System for Power Battery

In order to solve the compatibility problem of lithium batteries thermal management and cabin comfort in electric vehicles, a refrigerant direct cooling thermal management system is designed in this article, which is expected to balance the temperature demands of entire vehicle at different driving conditions. A one‐dimensional model is established to investigate the system performance, whose accuracy has been verified by the testing bench of a prototype fixed with a 16‐battery module. By the aid of this model, the thermal characteristics of the battery pack and the passenger cabin are obtained, and the compressor speed as well as the valves are selected as control units by sensitivity analysis of the important components. Subsequently, detailed control strategies around the variable frequency of compress speed and switch regulation for the valves are proposed based on the temperature changes, torque, and operating power consumption of the system in different control modes. Under the test conditions of the global light‐duty vehicle test procedure, it is found that cabin temperature can be quickly stabilized about 26 °C under different ambient temperatures. Additionally, the battery pack can be effectively maintained within the safe operating temperature range of 20–40 °C.

First realization of LHW–plasma coupling feedback control for long-pulse operation in EAST

To sustain good lower hybrid wave (LHW)–plasma coupling for long-pulse plasma operation, for the first time, coupling feedback control is designed and realized in EAST using a proportion integration differentiation method by choosing the reflection coefficient (RC) of LHW power as the reference for gas-puffing feedback, and including one pulse test and multi-pulse experiments. Experiments show that such feedback control can work correctly and maintains good LHW–plasma coupling effectively for a long time, suggesting the possibility of feedback control application on LHW–plasma coupling in long-pulse plasma. Furthermore, during the feedback control process of multi-pulse supersonic molecular beam injection (SMBI), the stored energy changes from 29 kJ to 58 kJ, and the energy confinement factor (H 89) increases from 0.98 to 1.45, implying a positive effect of coupling feedback on plasma performance. Experiments between SMBI puffing and the gas puffing system, fed by a piezoelectric valve near the antenna, are further investigated, showing that the response time of the RC with SMBI is faster than that by the piezoelectric valve. In addition, SMBI puffing on the electron-drift side of the LHW antenna is a little quicker than that on the ion-drift side. Studies suggest that such feedback control is effective for long-pulse LHW–plasma coupling, and the gas puffing by SMBI on the electron-drift side of the LHW antenna could offer an effective way to sustain good LHW coupling in steady-state operation in the future. Further optimization will be continued at a later date.

Stochastic exponential stabilization and optimal control results for a class of fractional order equations

The object of this study is to define existence, controllability and exponential stability results within a Sobolev-type fractional stochastic neutral equations of order 1<ω<2 with sectorial operator and optimal control. To do this, first, this study relies on the confluence of stochastic analysis, fractional calculus, sectorial operator, and the applicability of Sadovskii’s fixed point method. First, we highlight the existence of mild solutions to the fractional stochastic control equation and then introduce the concept of approximate controllability. Next, employing an impulsive Poisson system yields sufficient conditions for guaranteeing the exponential stability of the mild solution in the mean square moment. Further, our inquiry expands into the existence of optimal control. Finally, an example is provided to illustrate the obtained theory.

ВИКОРИСТАННЯ КОМП’ЮТЕРНИХ ТЕСТ-ТРЕНАЖЕРІВ ДЛЯ ВИЗНАЧЕННЯ І РОЗВИТКУ ПСИХОФІЗІОЛОГІЧНИХ ЯКОСТЕЙ ЮНИХ СПОРТСМЕНІВ

The current task for coaches nowadays is to choose an adequate method for assessing psychophysiological abilities, diagnosing, and further developing the psychophysiological qualities of young athletes to organize and correct training and competitive processes. The purpose of the study was to evaluate the effectiveness of computer test simulator programs for developing the psychophysiological qualities of young athletes, individualizing, and optimizing their training process. Using computer test simulators with the programs "MY_TIMER" and "FISHKI.INI", psychophysiological indicators were measured before and after training in five repetitions among 14 schoolchildren aged 12-14 from a secondary education institution. Statistical data processing was conducted using Microsoft Excel. Results: Unreliable differences (p ≥ 0.5) were found between the psychophysiological parameters of young swimmers before and after training. During the computer testing process, increases were observed in the total working time for each of the five tasks (indicating improved speed of thinking) by 18.5%, and in minimum, average, and maximum movement time by 14.3%, 11.1%, and 8.3%, respectively. However, the thinking factor decreased by 16% after training, which impedes the ability to perform operational tasks impromptu. Exercising in areas of high and moderate power leads to fatigue in the cortex of the large hemispheres of the brain, where operational control is carried out. Consequently, young athletes experience both physical and mental fatigue after training. The use of computer test simulators for determining and developing the psychophysiological indicators of young athletes is relevant, promising, and effective. These tools allow for the scientific substantiation of individualized training loads and the rapid assessment of athletes' current functional states. The "FISHKI.INI" program should be used for diagnosing and further developing psychophysiological qualities such as attention, operational thinking, and the dominance of figurative or visual-action thinking. This program enables the quantitative assessment of young athletes' characteristics and improves these qualities with high efficiency through the use of computer test simulators.

Development of a new modeling framework to describe sterile filtration of mRNA-Lipid nanoparticles

Sterile filtration is one of the critical steps in the production of lipid nanoparticle (LNP)-based biotherapeutics. However, LNP fouling can limit the overall capacity of the sterilizing-grade filter. Effective design and control of this unit operation enables a robust manufacturing process. The objective of this study was to examine the sterile filtration of mRNA-LNP through the dual-layer Sartopore 2 XLG membrane during both constant flux and constant transmembrane pressure (TMP) filtration experiments. The complete pore blockage model effectively described the fouling behavior at constant TMP, with the rate of pore blockage decreasing with increasing TMP. However, a novel modification of the complete pore blockage model was needed to describe the fouling behavior during constant flux operation, with the rate of pore blockage found to be a function of both the instantaneous TMP and the TMP gradient. This new model successfully describes the TMP profiles during constant flux operation at multiple fluxes and the flux profiles during constant TMP operation at multiple TMPs, all using the same model parameters. These findings establish a foundational framework that mathematically describes the fouling behavior of mRNA-LNP and can be used to design and optimize sterile filtration processes for this class of biotherapeutic.

Design Ship Fuel Level Prototype Based on LoRa Dragino 915 MHz

Abstract The development of monitoring and control system technology in the shipping industry today is experiencing very rapid development, one of the developing technologies is the fuel monitoring system. The fuel monitoring system is very important in the shipping industry because it relates to shipping operational costs and controls fuel usage during the voyage. Currently, fuel level monitoring is carried out using a sensor that sends data using a cable this has a problem because sending data via cable will have noise which will affect the measurement results. In this study, it will be discussed sending data from sensor measurements without using cables using the LoRa Dragino 915 MHz module, where the LoRa module will be divided into two points, namely LoRa Client and LoRa Server. The results of this study, the ship’s fuel level reading system can function properly and according to the specifications expected. The results of this prototype can read the condition of the fuel level in the fuel tank in real-time. In addition, the communication range between LoRa Client and Lora Server tested in this study can work with a distance of 170 meters in an open space and has a communication distance of 63 meters in a closed room.

The Influence of Non-Kinetic Actions on Multi-Domain Operations Command and Control

Abstract In the current context, the way military actions are carried out determines rethinking the military leadership and approaching it through the lens of hybrid, non-kinetic approaches, of high precision technologies and of those that integrate all areas of military operations. Potential adversaries are increasingly using non-kinetic warfare strategies that include subversive and disinformation campaigns, espionage and cyber attacks. Thus, non-kinetic actions are relevant elements for military operations requiring the implementation of new operating and command-control concepts. In modern military confrontations it is imperative that leadership systems project power and use both precise and long-range kinetic actions as well as non-kinetic actions with chain effects and substantial benefits in mission accomplishments.

Research on Simulation and Power Regulation Control Strategy of Fengning Variable-Speed Pumped Storage Unit

Abstract Variable-speed pumped storage unit demonstrates rapid power response and flexible adjustment of unit speed, significantly enhancing unit operational efficiency and the power system’s stability. This paper focuses on simulating the control strategy of the Fengning variable-speed pumped storage unit. First, the water pump/turbine and motor models are established based on the relevant parameters of the Fengning variable-speed pumped storage unit. Second, according to the distinct responsibilities of the governor and the excitation system, the control strategies of the unit in the power priority mode and speed priority mode are designed. Finally, we compare and analyze the power response characteristics of a single-machine infinite bus system under various operating conditions and control strategies. We also summarize the applicable scope and existing problems under different operating conditions.

Research on the operation and quality control of small rock hole shotcrete robot

A small rock shotcrete robot is applied in the deep tunnel dynamic disaster physical simulation system in order to simulate the final operation process of the tunnel project. The robot’s spraying operation and control include many kind of factors. In this paper, the main parameters affecting the spraying operation are analyzed by establishing the spraying model and coating growth model. For matching reasonably the spraying parameters, the matching equation of spraying quality and spraying gun parameter model and spraying feed speed has been derived. Based on the matching equation, the spraying gun structure and robot control system are designed, and the spraying distance and spraying gun movement velocity including horizontal and vertical driving have been controlled better. On the basis of theoretical analysis, a small rock hole shotcrete robot prototype has been developed and the spraying experiments have been finished. The experimental results showed that the model and equation established can guided the spraying quality control. With the increase of the injection elevation angle, the length of the long and short axes of the elliptic coating becomes larger, and the average thickness of the coating center is between 2.23 and 2.34 mm, which meets the design index of the injection robot. The rock hole shotcrete robot meet the design requirements.

Operational Control of an Unmanned Helicopter to Ensure an Emergency Safe Landing on an Unequipped Pad

Operational Control of an Unmanned Helicopter to Ensure an Emergency Safe Landing on an Unequipped Pad

IoT based Smart Surveillance with Landmine Detection and Alerts

The research uses a Node MCU microcontroller and Internet of Things (IoT) technology to create a robot for handheld applications. The robot has a night vision camera that connects to the internet, allowing it to take photos and videos from a distance, even at night. It also has a metal detector to find landmines and an infrared (IR) sensor to detect obstacles and prevent accidents. These sensors immediately notify and alert users through LCD screens, messages, and buzzers. The research aims to develop a robot with increased accessibility and user friendliness by offering simple manual and operator controls for robotic inspection. The high-definition camera provides clear photos and videos for detailed analysis of any suspects, helping to make informed decisions quickly and improve situational awareness. On detecting a landmine, the robot alerts the user through the email and displays the information on the LCD screen, enhancing the safety at checkpoints. The IR sensor helps the robot avoid obstacles by alerting the user and sounding a buzzer when something is detected at a close distance. This feature allows the robot to navigate complex environments safely. Overall the robot is designed to provide a smart surveillance by offering an immediate threat response to handle the security concerns in various situations.

A complete dynamic modeling of two-by-one gas-steam combined cycle unit for coordinated control design

The high penetration of renewable energy can potentially change the role of combined cycle gas turbines (CCGT) from load suppliers to flexible suppliers. However, the slow process in the dynamic modeling of the CCGT complete system restricts the design of its best flexible operation strategy. Therefore, this paper adopts the composite modeling method to establish a complete nonlinear dynamic model of a 2 × 1 CCGT including two gas turbines, two three-pressure heat recovery steam generators (HRSG), one steam turbine, and one heat exchanger. This model can reflect the dynamic characteristics of pressure and flow in the bottom cycle due to the changes in operating mode, which can guide the design of the flexible operation control strategy of the 2 × 1 CCGT. To verify the model’s accuracy, the simulated data were compared with the field data from a 900 MW cycle with the same configuration. The results show that the established model can accurately reflect the changing trend of variables during mode switching. The range errors of essential variables such as gas turbine (GT) power is 3.8 %, GT outlet temperature is 1.4 %, high-pressure drum pressure is 4.5 %, and the range errors of other variables are below 5 %, proving the fidelity of the established control model. The dynamic model established in this paper will be the basis for model-based controller design which can handle multi-objective optimization and constraints in flexible operations. Moreover, this model will be used to guide the design of multi-mode control and energy management strategies.

Integration of monitoring and operation ion source system in the DECY-13 cyclotron

Abstract In nuclear medicine, cyclotrons play a vital role as cyclic accelerators, producing radioisotopes for Positron Emission Tomography (PET) technology. Currently, the Accelerator Technology Research Center, National Research and Innovation Agency of Indonesia, is developing the DECY-13 cyclotron, which comprises several crucial components, including the ion source. The ion source generates ions that is accelerated to a specific energy level before being directed at the target. The ion source system of the DECY-13 cyclotron includes various supporting components, such as a cooling system, vacuum system, Magnet Power Supply (MPS), gas flow system, and cathode power supply. These components are currently operated independently, with manual monitoring by operators. To simplify and improve the operation, an integration project needed for supporting component of the DECY-13 cyclotron’s ion source. This integration utilizes LabVIEW software, the NI-9870 module, NI-9425 module, and NI-cRIO as the process operation controller. The successful development of the integration program ensures that the displayed data on the interface aligns seamlessly with data from each individual device. Consequently, the integration program serves as an effective tool for monitoring the operation of the DECY-13 cyclotron’s ion source.

Neuron Circuit Based on a Split-gate Transistor with Nonvolatile Memory for Homeostatic Functions of Biological Neurons.

To mimic the homeostatic functionality of biological neurons, a split-gate field-effect transistor (S-G FET) with a charge trap layer is proposed within a neuron circuit. By adjusting the number of charges trapped in the Si3N4 layer, the threshold voltage (Vth) of the S-G FET changes. To prevent degradation of the gate dielectric due to program/erase pulses, the gates for read operation and Vth control were separated through the fin structure. A circuit that modulates the width and amplitude of the pulse was constructed to generate a Program/Erase pulse for the S-G FET as the output pulse of the neuron circuit. By adjusting the Vth of the neuron circuit, the firing rate can be lowered by increasing the Vth of the neuron circuit with a high firing rate. To verify the performance of the neural network based on S-G FET, a simulation of online unsupervised learning and classification in a 2-layer SNN is performed. The results show that the recognition rate was improved by 8% by increasing the threshold of the neuron circuit fired.

Bibliometric analysis of wastewater treatment processes based on anaerobic ammonia oxidation process

In the realm of water treatment, the anaerobic ammonia oxidation (anammox) process stands out as one of the most innovative breakthroughs. Bibliometrics is an effective method for the evaluation of scientific results and the development of research trends in a particular field of study. Employing VOSviewer and CiteSpace, this study comprehensively analyzed scholarly articles and research trends related to anammox water treatment from 2014 to 2023. The findings revealed a total of 1225 articles in this domain, exhibiting an increasing trend every year in the world, while China emerges as the foremost contributor with close collaborations with the United States, Australia, and other nations. The examination of keyword co-occurrence and cluster network showcases coupled anammox-based reactor startup and opefrational strategies, nitrogen removal studies, nitrous oxide investigations and microbial community analyses are long-term academic endeavors. Furthermore, keyword burst and temporal network analysis,the operational control conditions, driving processes and analysis of microbial macrogenes for mainstream anammox in wastewater treatment plants need more research in the future to improve the feasibility of this technology in engineering applications. Additionally, a meticulous scrutiny of the top 20 landmark and highly cited research articles over the past decade underscores a few persistent intriguing themes, such as “mainstream anammox,” “biological nitrogen removal,” and “16 S rRNA genes,” In summary, this study contributes a nuanced understanding of the contemporary landscape and development trends within the field of anammox water treatment, which will shed light on the future research efforts.