Structure Of System Research Articles

An operating mode control method for photovoltaic (PV) battery hybrid systems

Depending on the PV power, load power, and battery status, the system may operate in different modes. The control loop may have to switch between operating modes. In practice, it is difficult to implement control loop switching because the transition and dynamic process are difficult to control. As a result, this paper presents a generalized mode control method that avoids loop switching across modes. First, system structure and topology are introduced. The operating conditions for both grid-connected and off-grid modes are then divided into six sub-cases. Furthermore, the control architecture, control loop, and reference transition for various scenarios are described. Finally, an experimental platform is built, and the results are presented to verify the proposed method.

Review of Compensation Topologies Power Converters Coil Structure and Architectures for Dynamic Wireless Charging System for Electric Vehicle

The increasing demand for wireless power transfer (WPT) systems for electric vehicles (EVs) has necessitated advancements in charging solutions, with a particular focus on speed and efficiency. However, power transfer efficiency is the major concern in static and dynamic wireless charging (DWC) design. Design consideration and improvements in all functional units are necessary for an increase in overall efficiency of the system. Recently, different research works have been presented regarding DWC at the power converter, coil structure and compensators. This paper provides a comprehensive review of power converters incorporating high-order compensation topologies, demonstrating their benefits in enhancing the DWC of EVs. The review also delves into the coupling coil structure and magnetic material architecture, pivotal in enhancing power transfer efficiency and capability. Moreover, the high-order compensation topologies used to effectively mitigate low-frequency ripple, improve voltage regulation, and facilitate a more compact and portable design are discussed. Furthermore, optimal coupling and different techniques to achieve maximum power transfer efficiency are discussed to boost magnetic interactions, thereby reducing power loss. Finally, this paper highlights the essential role of these components in developing efficient and reliable DWC systems for EVs, emphasizing their contribution to achieving high-power transfer efficiency and stability.

Calculation of the main operational characteristics of a tethered high-altitude ship-based system

Objectives. Currently, UAVs are actively used in many military and civilian fields such as object surveillance, telecommunications, radar, photography, video recording, and mapping, etc. The main disadvantage of autonomous UAVs is their limited operating time. The long-term operation of UAVs on ships can be ensured by tethered high-altitude systems in which the power supply of engines and equipment is provided from the onboard energy source through a thin cable tether. This paper aims to select and justify the appearance of such system, as well as to calculate the required performance characteristics.Methods. The study used methods of systemic and functional analysis of tethered system parameters, as well as methods and models of the theory of relations and measurement.Results. The issues of design and implementation of new generation tethered high-altitude ship-based systems were considered. A rational type of aerodynamic design for unmanned aerial vehicles was determined based on existing tethered platforms. The optimal architecture of the tethered system was defined and justified. The paper presents the appearance and solution for placement onboard the ship, and describes its operation. The main initial parameters for designing high-altitude systems such as take-off weight, optimal lift altitude, maximum power required for operation, structure of the energy transfer system, as well as deployment and lift time to the design altitude were selected and calculated.Conclusions. The methodology for calculating the necessary characteristics described in the paper can be used for developing and evaluating tethered high-altitude systems. These systems are capable of performing a wide range of tasks, without requiring a separate storage and launch location, which is especially important in the ship environment. The system presented herein possesses significant advantages over well-known analogues.

Novel Metamaterial Array-based Dual Port MIMO antenna using low profile substrate with feature Multiband, and high isolation for Sub-6G, IoT, and WiMAX Applications

Abstract TThis article represents a single-layered two-port MIMO antenna loaded into a compact plane-patterned metamaterial (MTM) structure for a 5G communication system. The antenna operates at three bands to investigate metamaterial properties in addition to diversity parameters, an arrangement of a series of arrays suggested a 2-port design antenna and a circular-shaped split ring resonator unit cell was developed. The design of a single port antenna utilizes 1 x 3 MTM unit cells for each component. This antenna operates within a frequency range ranging from 1 GHz to 15 GHz. Additionally, the suggested MIMO antenna offers a dominant isolation of -55dB. The measurement's results show that, with an entire antenna size of 112 mm x 26.5 mm and a 3.33 GHz bandwidth, the MIMO antenna is achieved with good efficiency and CCL < 0.35, considerable DG > 9.97dB, ECC < 0.18, and TARC < -9.97. The presented design is suitable for medical imaging, RFID, Bluetooth, Wi-Fi, WiMAX, IOT, satellite communication systems, and the 5G and sub-6 GHz spectrum.

Assessing Japan’s Taiwan Policy: Systemic Clarity, Political Survival and Bureaucratic Prudence

ABSTRACT What are the patterns of Japan’s foreign policy behavior toward Taiwan in the post-Cold War era? It is generally taken for granted that the origin of Japan’s foreign policy to Taiwan has been derived from a unitary strategic calculation related to East Asian international politics and its maritime security in the Asia-Pacific region. This conventional interpretation is insufficient. While external pressure and states’ relative material capabilities within the structure of the international system are crucial in explaining Japan’s policy toward Taiwan, interpretations based solely on the system level of analysis fail to provide a persuasive explanation of Japan’s foreign policy behavior. By conducting three case studies in 2006, 2019 and 2021 through the theoretical lens of neoclassical realism and empirical investigation based on primary and secondary Japanese-language sources, this article argues that Japan’s Taiwan policy has been shaped by the combination of three factors: the degree of systemic clarity at the international level, the Japanese prime minister’s political survival and bureaucratic prudence over the Taiwan issue at the domestic level. Since 2021, Japan has adopted a subtle approach to Taiwan, driven more by a defensive and precautionary response to the heightened sense of crisis across the Taiwan Strait.

Power Generation Optimization for Next-Generation Cruise Ships with MVDC Architecture: A Dynamic Modeling and Simulation Approach

The cruise industry is obliged by economic and environmental initiatives to pursue fuel-efficient solutions and lower ship exhaust emissions. The medium voltage DC (MVDC) distribution with intelligent power management has become a concept for next-generation onboard power systems as its energy-saving feature is to eliminate the frequency constraint and simultaneously optimize engine loads and speed in response to load variations. The incentive for this transition lies on one hand in the fuel efficiency consideration and the reduction of power losses from serial conversion stages. On the other hand, the DC-based technology has been conceived as high-power density design, thus significantly increasing the payload. This study investigates such potential benefits focusing exclusively on large cruise vessels. A highly representative model of the integrated power platform that incorporates all dynamic interactions from the ship hull and essential machinery typically installed on board cruise ships is proposed. The power management strategy also takes account of actual sea conditions and real-time operation requirements. The simulation results demonstrate that the optimization-based MVDC system is able to maximize the opportunity of search agents in finding optimum fuel efficiency areas throughout the scenario time. An analysis of the system structure weight and space reduction of the MVDC architecture is also performed through the utilization of more compact electrical distribution devices and very high power-dense combustion turbines.

A comprehensive survey of the application of swarm intelligent optimization algorithm in photovoltaic energy storage systems

With the rapid development of renewable energy, photovoltaic energy storage systems (PV-ESS) play an important role in improving energy efficiency, ensuring grid stability and promoting energy transition. As an important part of the micro-grid system, the energy storage system can realize the stable operation of the micro-grid system through the design optimization and scheduling optimization of the photovoltaic energy storage system. The structure and characteristics of photovoltaic energy storage system are summarized. From the perspective of photovoltaic energy storage system, the optimization objectives and constraints are discussed, and the current main optimization algorithms for energy storage systems are compared and evaluated. The challenges and future development of energy storage systems are briefly described, and the research results of energy storage system optimization methods are summarized. This paper summarizes the application of swarm intelligence optimization algorithm in photovoltaic energy storage systems, including algorithm principles, optimization goals, practical application cases, challenges and future development directions, providing new ideas for better promotion and application of new energy photovoltaic energy storage systems and valuable reference.

Actomyosin forces in cell migration: Moving beyond cell body retraction.

In textbook illustrations of migrating cells, actomyosin contractility is typically depicted as the contraction force necessary for cell body retraction. This dogma has been transformed by the molecular clutch model, which acknowledges that actomyosin traction forces also generate and transmit biomechanical signals at the leading edge, enabling cells to sense and shape their migratory path in mechanically complex environments. To fulfill these complementary functions, the actomyosin system assembles a gradient of contractile energy along the front-rear axis of migratory cells. Here, we highlight the hierarchic assembly and self-regulatory network structure of the actomyosin system and explain how the kinetics of different nonmuscle myosin II (NM II) paralogs synergize during contractile force generation. Our aim is to emphasize how protrusion formation, cell adhesion, contraction, and retraction are spatiotemporally integrated during different modes of migration, including chemotaxis and durotaxis. Finally, we hypothesize how different NM II paralogs might tune aspects of migration in vivo, highlighting future research directions.

Versatile, modular, and customizable magnetic solid-droplet systems

Magnetic miniature robotic systems have attracted broad research interest because of their precise maneuverability in confined spaces and adaptability to diverse environments, holding significant promise for applications in both industrial infrastructures and biomedical fields. However, the predominant construction methodology involves the preprogramming of magnetic components into the system's structure. While this approach allows for intricate shape transformations, it exhibits limited flexibility in terms of reconfiguration and presents challenges when adapting to diverse materials, combining, and decoupling multiple functionalities. Here, we propose a construction strategy that facilitates the on-demand assembly of magnetic components, integrating ferrofluid droplets with the system's structural body. This approach enables the creation of complex solid-droplet robotic systems across a spectrum of length scales, ranging from 0.8 mm to 1.5 cm. It offers a diverse selection of materials and structural configurations, akin to assembling components like building blocks, thus allowing for the seamless integration of various functionalities. Moreover, it incorporates decoupling mechanisms to enable selective control over multiple functions, leveraging the fluidity, fission/fusion, and magneto-responsiveness properties inherent in the ferrofluid. Various solid-droplet systems have validated the feasibility of this strategy. This study advances the complexity and functionality achievable in small-scale magnetic robots, augmenting their potential for future biomedical and other applications.

Study on the impact of large-capacity unit commissioning on the stability of the power grid using EEAC theory

Abstract In view of the fact that the commissioning of large-capacity units in areas with weak grids may reduce the transient stability of the system and lead to a decrease in the load capacity of the power grid, this paper analyzes the phenomenon. Combined with the actual situation of a certain power grid, the equal-area rule and the extended equal-area rule are applied in this paper. It is pointed out that in the planning and design of the power grid, factors such as the structure of the sending-end power system, the output of the unit, and the short-circuit capacity of the area should be fully considered, in order to avoid the drop in the transient stability of the power grid due to the structural characteristics of the large machine, large load and small network of the sending end system. Finally, through simulation analysis, it is proposed that the transient stability and splicing load capacity of the regional power grid can be improved by controlling the output of the unit, expanding the main transformer, quickly removing the fault, improving the characteristics of the generator and its excitation regulation system, increasing the terminal voltage and reactive power output of the leading group of units, and cutting the machine.

Harmonic absorption method for cement kiln power supply system under clean energy integration

Abstract To maintain the normal operation of the power supply system, a method for harmonic absorption in the cement kiln power supply system under clean energy access is proposed. We design a data acquisition structure for the cement kiln power supply system and extract the harmonic current signal of the power supply system through variational mode decomposition, harmonic compensation for the cement kiln power supply system under clean energy integration, and harmonic absorption of cement kiln power supply system through the current equivalent model. The experimental results show that the harmonic signal extraction accuracy of this method is high, and the difference between the consumed discharge power and the power demand is minimal. It can achieve a balance between power supply and demand through harmonic compensation, which is conducive to the stable operation of the power supply system.

Novel bamboo-raft-type floating structure (BRT-FS) assembled by FRP reinforced concrete tubes: Conceptual design and analysis

To improve construction efficiency in offshore engineering and extend service life of offshore platforms, a novel bamboo-raft-type floating structure (BRT-FS) assembled by FRP reinforced concrete tubes is proposed. It comprises four fundamental components: concrete tube, carbon fiber-reinforced polymer (CFRP) cable, holding beam, and bellow. This paper presents the structure system and structure design of BRT-FS. Separating load-bearing and buoyant functions ensures structural safety and ease of design. It has broad application perspectives in offshore construction due to its high corrosion resistance, designability, construction efficiency, and low crack control requirement. Furthermore, to obtain the operation conditions of BRT-FS, the mechanical performance is analyzed from two levels, which are hydroelastic analysis and structural analysis. Hydroelastic analysis is conducted under different wave directions, wave periods, water depths, and structural dimensions using a new finite element-boundary element (FE-BE) method. In a specify study case, a sensitive period around 11 s for head sea, around 7 s for oblique wave, around 5 s for beam sea are noted. The hydroelastic response is not significantly affected by water depth or transverse dimension. Structural analysis indicates that the structure can work in clam harbour sea with breakwater protection. Even after concrete tubes crack in higher waves, this new structure can still float with the inside bellows in theory. These preliminary findings confirm the feasibility of this novel structure. Structural details such as tube-tube joints, tube-beam joints, CFRP cable anchorages, and other connections will be further designed and tested in the future.

Optimization and analysis of battery thermal management system structure based on flat heat pipes and biomimetic fins

As one of the key components of electric vehicles, the enhancement of the performance of the power battery is closely intertwined with an efficient Battery Thermal Management System (BTMS). In the realm of BTMS, Flat Heat Pipes (FHP) have garnered considerable attention due to their lightweight structure and excellent thermal conductivity. Thus, a BTMS configuration scheme based on FHP is proposed in this study. Utilizing orthogonal design and fuzzy grey relational analysis as the evaluation methods, coupled with numerical simulations, an investigation into the influence of four structural parameters of the novel biomimetic fins (namely, the diameter, height, spacing of protrusions, and height of cooling fins) on the temperature distribution of the battery pack is conducted. The research findings indicate that to maintain the battery within an optimal operational temperature range, the optimal dimensional parameters should be controlled at 17.5 mm, 4 mm, 13 mm, and 90 mm, respectively. Subsequent sensitivity analysis reveals that the height of the protrusions exhibits the most significant influence on the maximum temperature of the module, whereas the height of the cooling fins exerts a considerable impact on the consistency of the module temperature. The optimized maximum temperature is determined to be 36.52 °C, with a temperature difference of 2.65 °C.

Torsional effect analysis of high-rise reinforced concrete space grid cassette multi-tube structure system

The manuscript introduces a new structural system called the reinforced concrete (RC) space grid cassette multi-tube structure for high-rise buildings. A case study building is analyzed using this system and compared to a conventional RC frame-core tube structure. Through modal analysis in the software “Midas Gen”, the torsional effect and control indices like inter-story displacement ratio, maximum displacement, etc. are compared between the two structural systems. The results show that the space grid cassette system has smaller displacement ratios, displacements, inter-story torsion angles, and thus better torsional resistance compared to the conventional frame-core tube system. Based on these analyses, the manuscript concludes that the RC space grid cassette multi-tube structural system has superior seismic performance and is more suitable for irregularly shaped high-rise residential buildings.

МЕНЕДЖМЕНТ В ОХОРОНІ ЗДОРОВ'Я. ОКРЕМІ ПРАВОВІ ТА ОРГАНІЗАЦІЙНІ АСПЕКТИ В ПОЛЬСЬКІЙ СИСТЕМІ ОХОРОНИ ЗДОРОВ'Я

In every democratic country that respects and protects human rights, human dignity and the functioning of the health care system are an extremely important element of society's development. In turn, the condition of the health care system should be one of the measures or factors proving the authorities' respect for society. Social changes, such as the increase in the wealth of citizens but also the aging of societies, cause debates and discussions on the functioning of the health care system, universality and access to medical services to become widespread. This is discussed by representatives of the medical community, representatives of groups currently «in power» and, above all, patients themselves. The structure of the health care system and the number of legal regulations creating this system in the Republic of Poland raise many problems. Their perception and analysis depend to a large extent on the nature of the evaluator, but one common element of such analyzes is the conclusion that the system is inefficient and requires changes. However, the scope of these changes is problematic. The medical community and management specialists see the need for changes in the management system combined with subsidizing the system. Patients, but also representatives of many communities, recognize the need for changes, but without incurring additional costs. Undoubtedly, the management system itself in facilities providing health services requires urgent changes. However, the complex structure of the system and its subjective and objective scope (including the multiplicity and diversity of facilities, various remuneration and employment systems) make it impossible to standardize activities. It should also be remembered that any changes must be made with the patient and his safety in mind.

Theoretical study on the effect of shear deformation on WSe2 as a cathode material for calcium ion batteries

AbstractIn this paper, the first‐principles method is used to calculate the electronic structure of the intrinsic WSe2 system and the Ca adsorbed WSe2 system under shear deformation, and the diffusion barrier of Ca on WSe2 is studied in depth. The results show that shear deformation can effectively reduce the band gap of WSe2 system, and shear deformation can easily lead to the transition from semiconductor properties to metal properties. The adsorption of Ca leads to the change of the band structure of WSe2. The contribution of Ca‐d electrons leads to an increase in the peak in the range of 3–6 eV. The shear deformation reduces the diffusion barrier of Ca on the WSe2 surface. This paper provides an improvement method for the application of WSe2 in the field of battery.

Centering cognitive neuroscience on task demands and generalization.

Cognitive neuroscience seeks generalizable theories explaining the relationship between behavioral, physiological and mental states. In pursuit of such theories, we propose a theoretical and empirical framework that centers on understanding task demands and the mutual constraints they impose on behavior and neural activity. Task demands emerge from the interaction between an agent's sensory impressions, goals and behavior, which jointly shape the activity and structure of the nervous system on multiple spatiotemporal scales. Understanding this interaction requires multitask studies that vary more than one experimental component (for example, stimuli and instructions) combined with dense behavioral and neural sampling and explicit testing for generalization across tasks and data modalities. By centering task demands rather than mental processes that tasks are assumed to engage, this framework paves the way for the discovery of new generalizable concepts unconstrained by existing taxonomies, and moves cognitive neuroscience toward an action-oriented, dynamic and integrated view of the brain.

Разработка кроссплатформенного приложения для управления робототехническим комплексом

A brief analysis of the approaches currently used to develop management programs is provided, their application features, advantages and disadvantages are identified. For the study, the development of a cross-platform appli-cation of control systems for robotic complexes (RTC) was chosen, using the example of RTC with MP-11 robotic manipulators. The structure of the control system includes a controller on the Arduino Mega 2560 Pro Mini board with a loaded low-level program and an upper-level program. The development is carried out on the platform.NET MAUI, which allows you to create an application for Windows, Android, and IOS operating systems on a single code base, i.e. the same code is automatically compiled for all operating systems, taking into account their features and applied elements. The control computer is connected via USB, mobile devices via Bluetooth, while data is programmatically transmitted via a serial port. The description of the modes of operation of the developed application, its functioning algorithms, indicating the features of execution for this type of programs and the appearance of forms with elements located on them is given. The program provides manual and automatic modes of operation, as well as control of not only the RTC, but also its model. The key features of this application are the use of a single code base and design for the implementation of desktop and mobile applications for various operating systems without using network resources, unlike web applications.

Synergistic enhancement of metal–organic framework-derived hierarchical porous materials towards photothermal conversion and storage properties of phase change materials

The design and synthesis of composite phase change materials that integrate photothermal conversion and latent heat storage have guiding significance for the efficient development and utilisation of solar energy. In this study, taking into consideration the advantages of metal–organic frameworks (MOFs) with adjustable structure and properties, HKUST-1-derived CuO/hierarchical porous carbon materials were employed and integrated with palmitic acid (PA) to synthesise composite phase change materials that exhibit exceptional comprehensive properties. The effects of different carbonation temperatures on HKUST-1-derived CuO/hierarchical porous carbon were analysed through a series of characterisations. The hierarchical porous structure in the blended system offers abundant pore structure and high specific surface area to prevent leakage of phase change materials. Composite phase change materials can maintain good shape stability and excellent thermal energy storage capacity. The thermal storage efficiency and photothermal conversion efficiency are 98.28% and 81.83%, respectively. Meanwhile, the thermal conductivity of the composite phase change material is 3.65 times that of pure PA. In conclusion, the MOFs derivative-based composite phase change materials designed in this study exhibited potential for thermal energy storage and can be applied to the field of solar energy conversion and storage systems.

Improved GNN based on Graph-Transformer: A new framework for rolling mill bearing fault diagnosis

The structure of the rolling mill system is complex and the operating conditions are changeable. Therefore, the interdependence between the data needs to be fully considered in the fault diagnosis of the rolling mill. Although graph neural network (GNN) is a powerful architecture based on non-Euclidean spatial data, the current method is difficult to represent the long-range dependence of rolling mill fault vibration signals. Simply increasing the depth of GNN is not enough to expand the receptive field of the model, because the larger GNN model may have the problem of gradient disappearance or transition smoothing. In order to solve the above problems, an improved graph neural network based on Graph-Transformer is proposed to diagnose the health status of rolling mill. This method first performs sliding maximum sampling on the spectrum of the original vibration signal to improve the frequency resolution and reduce the feature dimension. Second, the relationship between fault features is characterized by constructing affinity graph. Finally, the long-range dependency between paired features is learned through the readout module and the self-attention mechanism in Graph-Transformer and the diagnostic results are output by the classifier. The experimental results on the rolling mill platform show that this method can not only adapt to the changing working conditions of the rolling mill but also achieve excellent performance in the case of sample imbalance and strong noise.