Operation Methods Research Articles

Design of sliding mode controller with improved reaching law through self-learning strategy to mitigate the torque ripple in BLDC motor for electric vehicles

Brushless Direct Current (BLDC) motors and their evolution in electric vehicles (EVs) garner attention for their streamlined operation and control methods, enhancing driving range while reducing energy consumption. The primary objective is integrating sliding mode control to enhance BLDC motor capabilities, efficiently regulating speed and torque. The proposed sliding mode (SM) controller mitigates torque ripple and improves dynamic performance amidst fluctuating loads. Speed stabilization and torque control involve comparing reference and predicted speeds, with error feedback integrated into the SM controller. Integrating real-time rules and numerical data with an ANN (Artificial Neural Network)-Fuzzy self-learning algorithm empowers the SM controller to anticipate and mitigate error rates in the BLDC motor, efficaciously modulating motor torque with minimal ripple. Extensive MATLAB/Simulink model-in-loop (MIL) and hardware-in-loop (HIL) simulations demonstrate SM controller superiority over conventional PID, Fuzzy, and PID-Fuzzy controllers, with a rise time of 0.01 s, steady-state error of 0.001 %, settling time of 0.02 s, and peak overshoot of 0.066 %. Moreover, the experiment results show an impressive 29.41 % reduction in torque ripple and the development of efficiency maps to attain the maximum efficiency of 96.12 %. This initiative substantiates that the proposed SM controller to enhance BLDC motor efficiency and EV driving range across real-time conditions.

Harvesting condensate wastewater from commercial buildings air handling unit (AHU) drainage: An opportunity for water conservation

Water wastage is a matter of great concern, especially in this era of rapid development. Water consumption in high-rise and large-sized buildings is very high. Furthermore, high-rise buildings use a lot of water to generate the use of HVAC (Heating, Ventilation, and Air Conditioning) machines. However, the waste of water from this machine is also very disturbing. Therefore, it is important for us to realize that various ways and technologies can be used and utilized to prevent waste from happening. This research focuses on the wastage of water and waste water from air handling unit machines in high-rise commercial buildings around Penang, Malaysia. To make this study a success, several methods have been used, including interviews, observation at the study site, and conducting research through newspapers, journals, reports, and so on. Through this method, data to be analyzed can be collected. In this study, several factors lead to the waste of water from the Air Handling Unit machine, which will have adverse effects on the machine, the building, and also the environment such as condensate and drainage. To overcome the problem, it is important to implement proactive routine maintenance practices for the HVAC system to reduce the AHU wastewater. The finding incorporation of water-saving methods, such as using AHU wastewater for other non-potable purposes, is a practical and ecologically appropriate approach. This research emphasizes the potential for large water savings and environmental advantages in commercial buildings, calling for greater adoption of such methods in facility management and building operations.

Comparison of the methods of operation of the artificial intelligence system in the ultra-high sensitivity mode for the autonomous description of chest X-rays without pathology

Comparison of the methods of operation of the artificial intelligence system in the ultra-high sensitivity mode for the autonomous description of chest X-rays without pathology

On the development of reconstructive surgery of the maxillofacial region in Russia

The article examines issues related to the historical aspects of the development of reconstructive surgery of the maxillofacial area in Russia. A historical periodization of the process under study has been developed. Restorative and reconstructive surgery of faces received the most active attention after the end of the First World War, when such a type became necessary for a sufficiently large number of persons disfigured after injury. The article reviews monographs and manuals on general surgery with sections devoted to various methods of operations on patients with various defects and deformations of the face, restorative and reconstructive operations on soft tissues of the facea, methods of primary and secondary cheilo- and uranoplasty, as well as rhinoplasty. The exceptional contribution of domestic surgery to the possibility of using the Filatov stem for the needs of facial reconstructive surgery is shown. The history of the use of revascularized grafts to eliminate defects in the maxillofacial region, as well as the history of the introduction of techniques for using free flaps, is described in detail. The possibilities of transferring a block of tissue from distant parts of the human body to the defect with their revascularization are outlined. Modern ideas about a number of biochemical, histological and morphological changes in the area of the defect and graft when replacing lost bone in the maxillofacial area are highlighted.

Factorial experimental design for removal of Indigo Carmine and Brilliant Yellow dyes from solutions by coagulation

Textile and food industries produce huge amounts of wastewaters containing dye residues. When these wastewaters are discharged to receiving surface waters like as lakes and rivers, aesthetically unpleasant situations form. Therefore, these wastewaters should be treated. Wastewater treatment is sometimes an expensive operation and cheap methods should be developed. The removal of Indigo Carmine (I.C., Acid dye) and Brilliant Yellow (B.Y., Azo dye) from synthetically prepared solutions was studied by coagulation using iron chloride salt in a batch reactor at room temperature. As an experimental approach, two leveled factorial design with three factors was applied as a function of pH (4-12), iron chloride amount (0.1-0.4 g/500 mL) and dye concentration (100-200 mg/L). Low pHs supported to removal of these two dyes. The results showed that 100% I.C. dye removal and 90.5% B.Y. dye removal were achieved. The all parameters were statistically insignificant for both the dyes. Indigo Carmine and Brilliant Yellow dyes were removed from solutions successfully. The applied treatment method was evaluated as promising due to low sludge production, low cost, low coagulation duration and high performance. A time span of 5 minutes was found as enough for removals of both of the dyes. After treatment of I.C. and B.Y. dyes by coagulation, the coagulated dyes were determined as unreusable due to iron complex by these dyes. Flocculation was found to be ineffective. A continuous flow reactor was successfully adopted for these dyes.

Practical Aspects of Using Modern Laser Scanning Techniques for Measuring Mine Excavations

Abstract For more than a dozen or so years now, there has been growing interest in the use of modern laser scanning measurement methods in numerous mining operations engaged in underground excavation. However, the simple possession of a scanner does not guarantee satisfactory measurement results. This study sets out the results of scanning mine excavations in an active mine and describes the current guidelines on various aspects of the measurement process. These guidelines were developed on the basis of several hundred measurements carried out over the last dozen or so years. This study also outlines the typical measurements errors observed over the course of many years. These errors, resulting partly from hardware limitations and partly from human error when planning or actually performing measurements, were an important factor behind the introduction of standards regulating underground measurements. This study discusses in detail not only scanning that utilises traditional stationary laser scanners but also scanning based on mobile scanners. It also presents possible areas of future technological development in line with global trends.

Digital twin-driven intelligent operation and maintenance platform for large-scale hydro-steel structures

Large-scale hydro-steel structures (LS-HSS) are pivotal in hydraulic engineering, boasting high lift, expansive apertures, and discharge capacities. Conventional methods of operation and maintenance for LS-HSS require a digital revolution to ensure safety, reliability, and durability. This study introduces a novel approach, harnessing the power of a digital twin (DT) to integrate physical and virtual elements in LS-HSS operation and maintenance seamlessly. A digital twin modeling framework of LS-HSS operation and maintenance is first presented, incorporating five levels of a physical entity, a virtual entity, DT data, services, and connections. Subsequently, a DT-driven intelligent operation and maintenance (DT-IOM) platform is constructed and applied, which features real-time mapping, closed-loop control, dynamic health assessment, and intelligent decision-making. This platform provides a pathway for digitally transforming conventional LS-HSS operation and maintenance and paves the way for a new era of intelligent infrastructure management. The proposed approach has been successfully implemented and validated with multiple engineering projects, including radial gates of reservoir spillways, plain gates of flood discharge orifices, and emergency gates of pumped storage power stations. The impressive results demonstrate a significant anomaly response and processing efficiency improvement of over 60%. Moreover, the platform has substantially reduced field inspection time and equipment failure rate by approximately 50% and 20%, respectively. These tangible benefits further highlight the platform’s functional advantages, including its capability for IoT connection, modeling and integration, virtual-real interaction, 2D/3D visualization, and service expansion. The results demonstrate the unique features in the closed loop of perception, analysis, decision-making, and optimization for DT-IOM, especially for integrating data, models, knowledge, and services in LS-HSS intelligent operation and maintenance.

Fine‐solids removal by foam fractionation in a low‐salinity marine recirculating aquaculture system (RAS)

AbstractObjectiveWe sought to evaluate several methods of operation of a foam fractionator for fine‐solids removal (organic matter < 55 μm) in a commercial‐scale, low‐salinity (11–13‰) recirculating aquaculture system (RAS) for marine finfish production.MethodsThe total suspended solids (TSS) concentrations of the RAS microscreen drum filter inflow and outflow and the foam fractionator outflow were obtained under various foam fractionator operating conditions. The outflow TSS concentration of the drum filter also served as the inflow TSS concentration for the foam fractionator. Sample collection for TSS determination was divided into two categories: particles greater than 55 μm and particles less than 55 μm. The difference between inflow and outflow TSS concentrations was used to determine the removal percentage for each particle class of each unit. Additionally, the volume of foammate produced under operating conditions by the fractionator and the amount of solids contained within the foammate were quantified. Flow through the foam fractionator was also obtained to determine the amount of solids removed per volume of influent water treated.ResultThe influent TSS concentration for the seven different operating conditions evaluated ranged from 4.8 to 6.3 mg/L, with the percentage of particles less than 55 μm ranging from 69.75% to as high as 86.1%. The drum filter removed over 90% of the particles larger than 55 μm and removed 8–26% of the particles smaller than 55 μm. No difference was observed in the overall removal efficiency of the drum filter, which ranged from 19% to 44%. There was no significant difference in the foam fractionator overall removal efficiency, which ranged from 6.5% to 38.5%. Operating the foam fractionator at a high water head height (HHH) with the submersible aspirating impeller provided the greatest removal percentage of particles less than 55 μm (26.9%). However, at the HHH, only half the amount of solids was removed compared to using a Venturi injector with ozone, but energy use was roughly 26% greater.ConclusionThe foam fractionator was operated at the HHH, about 0.31 m higher than the low water head height, for production operation. Additionally, Venturi injection of ozone provided the greatest removal of solids for the volume of influent water treated over a 12‐h operational period. The submersible aspirating impeller showed potential for low‐cost use with reasonable solids removal and warrants further evaluation.

Nonvolatile photoelectric memristor for reconfigurable Boolean logic operation and data storage

Photoelectric memristors have the advantages of highly parallel computing and large-scale interconnection, which provides a promising method for reconfigurable logic operations and greatly promotes the development of new memory computing technology. In this paper, a photoelectric memristor was fabricated using natural gelatin and water-soluble CdSe/ZnS quantum dots with a shell structure. Under light stimulation, the device undergoes photoelectric effects in the dielectric layer, generating electron–hole pairs and causing the device to transition from a high-resistance state to a low-resistance state. Seven nonvolatile logic functions are achieved using three wavelengths of light excitation devices. Compared with traditional electrically controlled memristors, emerging photoelectric memristors are more attractive because they can integrate the advantages of photons and electrons.

Wargaming in Information Warfare Training: A Study of Finnish Officials

In the digital age, information warfare has become a significant global concern, with malicious actors exploiting various media to manipulate public opinion, destabilising governments, and sowing discord. Automated and algorithmic tools are used to spread false and misleading information on social media platforms, and states have been unable to control the spread of it. In addressing new challenges, national governments globally reassess strategies, communications, and responses to adapt to evolving threat environments. To counter information influence activities, it is crucial to have informed, educated, and well-trained communicators. This case study focuses on the innovative use of wargaming in training government officials, providing them with abilities to respond to different tactics and methods of malign influence operations. This article is based on an information warfare exercise conducted in January 2024 involving 27 Finnish officials from various ministries and agencies critical to national security. The participants participated in an interactive simulation, where they explored and responded to challenges related to disinformation campaigns and other tactics designed to manipulate and influence information within a hybrid warfare context. The players were divided into two teams: red and blue, with the reds assuming the role of the offensive team while the blues took on the defensive role. The teams competed for control over the information space, employing various information warfare methods. After the exercise, each participant was asked to complete a post-exercise survey to evaluate the knowledge acquired and the exercise's overall usefulness, including scenario clarity and the effectiveness of role-playing. We also explored potential differences in perceptions and experiences between inexperienced and experienced players in the wargaming exercise. Key findings revealed the effectiveness of wargaming as an educational tool, particularly benefiting novices over experienced players. Role-playing proved valuable, emphasizing the importance of explicit scenarios for effective engagement. The study highlighted cross-departmental cooperation's significance, facilitating a dynamic learning environment.

Ciphertext policy attribute-based encryption scheme supporting Boolean circuits over ideal lattices

Considering the existence of fast implementation methods for multiplication operations over ideal lattices, we constructed a selectively secure ciphertext policy attribute-based encryption scheme supporting Boolean circuits based non-monotonic linear secret sharing scheme. It uses the trapdoor generation algorithm TrapGen to generate the public parameters and the preimage sampling algorithm SamplePre to embed the public parameters and randomness into the user’s secret key, which achieves the randomization of the secret key. The sharing and reconstruction of the secret in the encryption and decryption algorithm are achieved by a non-monotonic linear secret sharing scheme. Compared to the existing ciphertext policy attribute-based encryption schemes based on a similar sampling algorithm, the size of the ciphertext is significantly reduced.

Rocket science unveiled: A differential equation exploration of motion

Through the perspective of differential equations, the report "Rocket Science Unveiled" explores the amazing invention of rocket propulsion. In order to study, comprehend, and forecast the behavior of rocket engines, differential equations are essential. In order to better understand and analyze this intricate anomaly, the report aims to investigate the underlying mathematics of rocket propulsion and how differential equations work. We apply the differential equation to clarify the fuel consumption and thrust generation rates. In addition, we utilize Newton's rule of motion to explain the relationship among thrust, mass, and acceleration. Working on this study allowed us to discover the anticipated outcome for both position location and spacecraft position determination. For iterative operations, we used Euler's approach because the analytical calculation of differential equations is complicated, we used Euler's method for iterative operations. Knowing the rocket's initial or previous value allows us to locate or establish its placements with ease.

Investigation of Pedestrian and Driver Behaviors at Push-Button Crosswalk on Main Arterials of Urban Roads : A Case of Samsun City, Türkiye

There are different types of crosswalks for pedestrians to cross the street and different methods of operation. Signalization can be used in the operation of at-grade and controlled crosswalk. In these crosswalks, signaling is activated by pedestrians pressing buttons placed on the crosswalks. In this type of crossing, pedestrians press the button to cross the road and the signaling system detects the request. Within a reasonable time, the system turns red for vehicles and green for pedestrians, allowing pedestrians to cross the street safely. However, these systems have some drawbacks. Various observation and data collection studies were carried out at the pilot pedestrian crossing on Atatürk Boulevard in Atakum district of Samsun province. In these studies, 227 pedestrians crossing the crosswalk and 791 vehicles stopped at red lights during the crossing of pedestrians were examined. As a result of the data obtained in line with pedestrian and driver behaviors, it is aimed to determine the operational problems in signalized crosswalk with pedestrian warning and to increase efficiency with the studies to be carried out.

Wireless Communication-aware Path Planning and Multiple Robot Navigation Strategies for Assisted Inspections

Among the many challenges robots encounter in the mining industry, exploring confined environments receives significant attention. This work tackles problems associated with robot communication in hazardous and confined environments, where its cluttered and extensive nature frequently precludes traditional cable-based and wireless solutions. Our methods resort to off-the-shelf long-range radio frequencies to profile the signal propagation behaviour over the geometrical map to assist navigation algorithms that seek to preserve the connection. We consider mathematical models to predict signal power behaviour and serve as input to path planning. We also propose a semi-autonomous leader-follower scheme, with signal repeater units forming a mobile wireless network to enable inspection in hard-to-reach locations. Finally, we present a multi-robot connection-aware system, combining path planning based on radio signal power with multiple robot navigation. Results show the applicability of the proposed solutions, generating single and multi-robot paths for optimal signal reception based on power estimation, thus enabling operations in remote and isolated areas with no line-of-sight between the command base and the robotic inspection device. Experiments conducted in long corridors and in a representative mining environment using the EspeleoRobô and Pioneer platforms demonstrate significant improvements over the traditional communication methods for robotic operation regarding communication quality and inspection range limits.

Capacitive deionization technology with multi-stage treatment as an efficient desalination process for agricultural irrigation

Novel capacitive deionization (CDI) technology is recognized as a cheap desalination method and holds a promise to be deployed in low-profit fields such as agricultural and municipal works. In this study, the application feasibility of CDI technology in agricultural irrigation is thoroughly investigated. The desalination performance of three operation methods (“low flow rate”, “high applied voltage”, and “two-stage treatment”) are compared for treating artificial brackish water of 2000 mg L−1 to a set desalination target (600 mg L−1). Among these three methods, “two-stage treatment” overwhelms the other two methods regarding several desalination indicators, achieving a decent productivity (1.5 L h−1 m−2) with a small energy input of 1.4 kWh m−3. The modified Donnan model indicates that energy dissipation is mitigated in a high flow rate adopted in two-stage treatment, and meantime a high desalination capacity and a good charge efficiency are achieved. In addition, desalinated water with a salt concentration gradient is produced by the CDI module for tomato seedlings irrigation. Compared with the tomato seedlings irrigated by feedwater (2000 mg L−1), the total length and the biomass weight of those irrigated by desalinated water of 300 mg L−1 increase 51.1 % and 119.8 %, respectively. The research accomplishes a proof-of-concept of the agricultural application of CDI technology, and provides reliable data as the foundation for its future practical operation.

Deconstructing a form of hybrid investment fraud: Examining ‘pig butchering’ in the United States

Cyber-enabled fraud has transformed, becoming more complex and making it harder for targets and law enforcement to detect its occurrence. This study aims to recontextualize a major manifestation of this transformation, a crime called hybrid investment fraud, colloquially known as pig butchering. Hybrid investment fraud describes a cyber-enabled fraud whereby criminals gain the trust of victims by forming connections and relationships, and then exploit this trust by using a series of confidence building and coercive measures designed to encourage victims to continuously invest in securities or commodities until they become unable or unwilling to continue to make payments or the offenders become unreachable. This study further aims to address the existing knowledge gap by focusing on understudied elements of this fraud, such victim and offender characteristics and the ways hybrid investment fraud is perpetrated. To achieve this, we conducted an in-depth analysis of more than 1,300 news articles and court documents between January 1, 2018, and November 1, 2023, to identify 59 cases of hybrid investment fraud targeting victims in the United States. This article both situates hybrid investment fraud within the broader fraud literature and conducts a comprehensive of analysis of hybrid investment fraud cases to identify the types of hybrid investment fraud committed, their impact, victim and offender demographics, and offenders’ tactics, tools, and methods of operation. The findings from this study can inform criminal justice practices and future research of this fraud.

Comparative analysis of working principles and applications of MOSFET and HEMT

Semiconductor materials are currently one of the most core materials in the worlds high-tech industry, and the research and development of semiconductor materials is related to the improvement of human technological level. This paper presents a comparative study of Metal-Oxide-Semiconductor Field-Effect Transistors (MOSFETs) and High Electron Mobility Transistors (HEMTs), two pivotal components in electrical engineering, each with unique characteristics and functions. Despite structural similarities, MOSFETs and HEMTs differ significantly in operation and conduction methods. MOSFETs rely on an inversion layer formed at the semiconductor-oxide interface, controlled by gate voltage, for electron conduction. Conversely, HEMTs utilize a two-dimensional electron gas (2DEG) at the interface of materials like Gallium Nitride and Aluminum Gallium Nitride, offering high electron mobility crucial for performance. Both share similar I-V characteristics but differ in performance under various conditions. MOSFETs are cost-effective, ideal for mass production and general applications, while HEMTs excel in stability and performance in extreme conditions, suitable for high-performance needs. This study underscores the importance of selecting the right component based on application-specific requirements, highlighting MOSFETs for cost-efficiency and HEMTs for challenging environments. This article will provide some guidance for the research of MOSFET and HEMT.

Influence of the Development of Internet Big Data on College Students' Music Education

Under the background of globalisation and diversification, how to construct a music culture with national characteristics and develop music education with both diversity and localisation is a major issue that music education theory and research in China must face up to. This study begins with a theoretical overview and uses big data analysis to construct a framework for teaching localisation. Then the localisation methods of educational concepts and practical operations are sorted out, and the construction of the localised teaching model of Orff music pedagogy is introduced. Finally, this paper describes the big data analysis of the localised teaching model in terms of cluster trend analysis and determining the number of clusters analysis. The results show that the Chinese music pedagogy of Orff is realised on the basis of improving students' music knowledge and achieving their all-round development. The experimental data effectively improved the speed and accuracy of the big data analysis algorithm. This study is significant for the localised music education system in China.

Tailored treatment of female indirect inguinal hernias by using single-port laparoscopic percutaneous internal ring suture: a comparison between children and adults

PurposeTo compare the outcome of indirect inguinal hernias repaired by using single-port laparoscopic percutaneous internal ring suture (SPIRS) between the pediatric and adult females.MethodsThe medical records of females who were clinically assessed to have inguinal hernia from Oct. 2016 to May 2022 were reviewed. Patients who received laparoscopy for the diagnosis of the hernia type and customized treatment according to their hernia type were included, while those who chose other operation methods initially were excluded. The patients were divided into the adult and pediatric groups based on their age. The demographic characteristics, hernia types, operation durations, and outcomes were analyzed between these two groups.ResultsA total of 65 adults and 60 children were included in this study. The median age was 38 years. (range: 23–88) for group A and 3 years (range: 0.1–16) for group P. Indirect hernias were present in 85% of adults and 100% of children. All the indirect hernias were repaired by SPIRS uneventfully. Incidence of contralateral patent processus vaginalis was 24% in adults and 50% in children (p = 0.016). The average operation time was 22/46 min (one/two sides) for the adults and 9/15 min (one/two sides) for the pediatrics (p < 0.010 for both). The overall complication rates were 5.4% and 3.3% for the adult and pediatric group respectively (p = 0.106). No recurrence was observed in the pediatric group, but two adults experienced recurrence and another had chronic postoperative inguinal pain, necessitating reoperation. The mean follow-up period was 38.6 ± 15.4 months for adults and 42.8 ± 18.9 months for children (p = 0.198).ConclusionOur results support that the pathogenesis of indirect inguinal hernia for the female adults is due to the non-obliteration of a congenital processus vaginalis. Tailored treatment of the female IIH by using single-port laparoscopic percutaneous internal ring suture may be an alternative for the management of female IHs.

The Experiences of Practical Nurse Students in Promoting the Rehabilitation of the Elderly Through Nursing Care and Its Education – A Secondary Publication

The significance of rehabilitation-promoting nursing care is emphasized in aging Finland. According to studies, rehabilitation-promoting nursing care enhances the functional capacity of the elderly. The Elderly Services Act obliges municipalities to create a plan to support the elderly population, emphasizing living at home and rehabilitative measures. A large portion of graduated practical nurses will be working with the elderly, so the education of practical nurses must meet the needs of the workforce. The study aimed to produce new information on the implementation of rehabilitation-promoting nursing care in the elderly services system and on the education of rehabilitation-promoting nursing care for the elderly in vocational institutions. The research data was collected in the fall of 2020 through individual theme interviews with practical nurse students (n = 8). The data was analyzed using inductive content analysis. The experiences of practical nurse students regarding rehabilitation-promoting nursing care for the elderly were related to nurses’ time management, organizational practices, nurses’ competence, nurses’ attitudes, nurses’ methods of operation, organizational development, implementation and development of practical teaching, factors affecting the use of aids, and the technology of aids in the future. In conclusion, it can be stated that the content of education and practical work life do not align. It is essential to increase competence in rehabilitation-promoting nursing care and develop organizational practices.