Flexible System Research Articles

A Grid-Less Flexible Tactile Sensing System Based on Deep Neural Network for Two-Point Localization and Shape Recognition

A Grid-Less Flexible Tactile Sensing System Based on Deep Neural Network for Two-Point Localization and Shape Recognition

Friction-induced nonlinear dynamics in a spline-rotor system: Numerical and experimental studies

Excessive vibrations induced by intrinsic internal friction in spline joints critically impact the reliability and safety of high-speed rotating machinery. To address this concern, this paper presents experimental and numerical research on a flexible rotor system subjected to frictional contact within the spline joint. Experiments are conducted on a scaled rotor test rig designed to emulate the tail rotor drive shaft of helicopters, aiming to explore vibration behaviors under various operating conditions. A reduced-order mathematical model based on the test rig, considering the multi-interface friction of the spline joint and deformation coordination with a flexible coupling, is formulated. The numerical study, which incorporates both stability analysis and transient nonlinear dynamics, is then presented to quantitatively evaluate the occurrence conditions and excitation mechanisms leading to friction-induced instabilities. A parameter study is further conducted to elucidate the roles of various parameters in shaping self-excited vibration behaviors. The results reveal that the cross-coupling of frictional forces within the spline joint acts as the driving force of instabilities at supercritical speeds, with the resulting self-excited responses dominated by the frequency of the first critical speed. The study also highlights the necessity of integrating experimental and numerical analysis to better predict and understand the self-excited vibration phenomena in the spline-shaft systems.

Examining the experiences of mid-career nurses in hospitals: a phenomenological study

Background The turnover of new and mid-career nurses has been increasing, leading to challenges in recruiting and retaining nursing staff. Objectives Securing and retaining mid-career nurses is crucial for ensuring high-quality care. However, little is known about mid-career nurses’ experiences regarding turnover. This study aimed to understand the experiences of mid-career nurses and identify strategies to enable mid-career nurses to maintain long-term employment in health services. Design Colaizzi’s phenomenological methodology was adopted to illuminate the subjective meaning derived from the work-related challenges of mid-career nurses, leading to turnover. Focus group interviews were conducted to delve into the work challenges faced by mid-career nurses. Method The participants were 23 mid-career nurses working in one tertiary hospital and six secondary hospitals across three Korean cities, recruited using purposive and snowball sampling. The inclusion criteria entailed a minimum of three years of nursing experience and current employment within a designated department or clinical area within the hospital environment, commonly known as a nursing unit. Such units encompassed a range of clinical settings, including medical-surgical units, intensive care units, and emergency rooms. The interview data were transcribed verbatim, and significant statements were extracted from abstract sentences to derive themes through an analytical process. Results Analysis of the work experiences of 23 mid-career nurses in medical institutions yielded 15 themes and 4 theme clusters derived from 353 meaningful statements. These theme collections were identified as ‘Difficulties endured as a mid-career nurse’, ‘Meaningless and regrettable new graduate nurses’ education’, ‘An inexpressibly poor work environment’, and ‘Systems and policies needed to remain in the hospital’. Conclusions Difficulties faced by mid-career nurses including the establishment of an education and career development system, provisions for guaranteed leave, a diverse and flexible work system, opportunities for effective communication, and engagement with the opinions of mid-career nurses should promptly be addressed.

Research on engineering technology of compact thermoacoustic air conditioner for vehicles

Thermoacoustic refrigeration technology presents a promising solution for sustainable and efficient air conditioning in vehicles. However, traditional thermoacoustic systems typically employ rigid resonant tubes, which pose challenges in terms of assembly and spatial layout during experimentation. Additionally, electric heating is predominantly utilized as the heat source in most experimental setups.To address the need for compact thermoacoustic air conditioning systems suitable for vehicle applications, this paper introduces the concept of employing flexible resonant tubes in heat-driven thermoacoustic refrigeration systems. Our study begins by constructing a heat-driven thermoacoustic refrigeration platform designed to simulate real automotive exhaust conditions. The DeltaEC software is employed to optimize the design of each component within the system.Both flexible and rigid resonant tubes are used in experimental research. Our findings reveal that the pressure amplitudes measured from experiments using both types of tubes closely match the simulated sound field. Operating at 8.7 MPa, the cooling capacity of the thermoacoustic system with flexible tube is 3.4 kW at 10 ℃. Using more gentle bending of flexible resonant tubes can reduce small losses caused by bending in rigid resonant tubes. Consequently, under similar working conditions, the cooling capacity generated by the system employing flexible resonant tubes slightly exceeds that of systems employing rigid resonant tubes. Furthermore, our study demonstrates a thermoacoustic conversion efficiency of 20.8 % and a refrigerator refrigeration efficiency of 2.34.These findings provide empirical validation for the use of flexible resonant tubes within vehicle exhaust heat-driven thermoacoustic refrigeration systems. The experimental results clearly demonstrate the ability of vehicle exhaust as a heat source to provide heat for thermoacoustic systems, and the ability of flexible thermoacoustic systems to generate sufficient cooling capacity. Ultimately, this research contributes to the advancement and practical implementation of thermoacoustic air conditioning within vehicles.

Determination of Permanent Deformations of Non-Cohesive Soils in Pavement Structures under Repeated Traffic Load

One of the main types of distress in pavement structures is rutting, which may also reduce serviceability significantly. Most design methods typically attribute rutting to the asphalt layer alone, proposing that it can be managed by controlling vertical deformation or stress at the subgrade’s top. Furthermore, these methods frequently lack precise measurements for rut depth. On-site measurements show that the majority of permanent deformation occurs in the unbound layers beneath the asphalt; attention should be directed towards these layers. In recent literature, there are calculation methods that account for accumulating strains in soils. However, further investigation is needed regarding the effect of soil properties and the significance of the pavement cross-section. The literature is also somewhat contractionary regarding the origin of permanent deformations. In this research, the residual settlement of soils (base, subbase, and subgrade) under flexible pavement systems was analyzed due to the repeated traffic loads. Rut depths were calculated and analyzed using the High-Cycle Accumulation (HCA) model. The different behaviour in each course of the pavement system is discussed to reveal their contribution to total ruts. The effect of the grain size distribution of the subgrade was analyzed, and its significance on the rutting depths was demonstrated. Standardized pavement cross-sections with different asphalt thicknesses were evaluated, and the calculated settlements of the pavement originating from the ground during the design lifetime are also presented. It is shown that, with the same number of repetitions, the settlements calculated in each traffic load class are proportional to the thickness of the asphalt course. The contribution of the base, subbase, and subgrade courses to the total settlement is also presented for different subgrade types and traffic load classes.

A sustainability-oriented approach for performance assessment of existing buildings and a case study

The practice of sustainable buildings has become a general trend in urban development. Yet, with the rapid development of urban renewal, the performance of existing buildings often fails to meet the actual needs of sustainable urban development. To improve the performance of existing buildings, it is urgently needed to transform the existing structures and upgrade their functions and facilities. However, the pertinent guidelines have often been unclear for assessing the performance of existing structures, and a sounder and quantitative sustainable performance assessment approach has been lacking to guide decisions on the restoration, protection, or demolition of existing buildings. Based on a multi-expert consultation methodology, we proposed a revised flexible comprehensive assessment system and a comprehensive sustainability assessment approach. The system includes 4 categories, 7 quantitative and 47 qualitative indicators. Specifically, the assessment system involves a series of steps: 1) building a hierarchical model, 2) defining assessment indicators/items and constructing a judgment matrix, 3) determining the weight coefficients of the indicators, 4) collecting/calculating quantitative and qualitative data, 5) analyzing the data and results, and 6) drawing the assessment conclusions. A case study was presented to demonstrate the application of the approach. Compared to current practices, this comprehensive assessment system may serve as a scientifically sounder and quantitative approach to guide sustainable development of existing urban buildings.

Tribo-dynamic modeling method and application to three-dimensional flexible PRL system

Research on the tribo-dynamics of the piston-cylinder liner (PCL) and piston ring-cylinder liner (PRCL) is vital due to their role in generating over 50 % of total engine friction loss and the impact on carbon emissions. Traditional studies, hindered by the structural and functional differences between pistons and rings, required separate simulation models, often overlooking crucial coupling characteristics. A unified tribo-dynamics modeling method for the piston-ring-liner (PRL) system is proposed in this paper, integrating the ring pack and piston into one multi-body system. This article models with global coordinates, unifying the form of governing, film thickness, and load equations of discontinuous lubrication domains for more efficient dynamics-lubrication coupling. The described method is applied to a marine engine, and the new tribology characteristics discovered after calculations are exhibited. It shows how piston deformation impacts ring tribology, indicating that increased profile height reduces the squeezing effect by allowing more ring movement. Additionally, ring assembly position significantly affects tribology parameters' circumferential distribution. Installing the ring with the end gap facing the piston pin side should be avoided, as it maximizes the negative impact of elastic force and secondary motion, deteriorating lubrication.

Arbitragem e energia no Brasil

The electric industry encompasses the segments of energy generation, transmission, and distribution. It comprises intensive infrastructure investments and energy commercialization. Events related to energy transition and the integration of disruptive technologies have altered the sector’s landscape, requiring system flexibility and increased regulatory proactivity. Additionally, it demands structural, operational, and market changes. The sector is disruptive in terms of governance and operational, market, and legal aspects. In the 2000s, the introduction of competitive areas in the electric industry was the first step towards the use of arbitration, driven by regulatory reforms and in response to the country’s energy crisis, which also led to the first arbitration in the Brazilian electric sector involving the Public Administration. Law nº 10.848/2004 currently makes arbitration mandatory in energy trading contracts managed by the CCEE. Arbitration also finds space in other forms of energy negotiation, such as contracts for mini and micro-distributed generation and energy derivatives. The context of modernization increased renewable energy production and market opening create opportunities for arbitration expansion. There is also potential for further development in enabling relationships of capital-intensive electric industry activities. The paper provides data on the state of the art of these contracts in the Brazilian electric sector, indicating under what circumstances arbitration could enhance governance in the industry.

Artificial intelligence applications in solar energy

Renewable energy research has become significant in the modern period owing to escalating prices of fossil fuels and the pressing need to reduce greenhouse gas emissions. Solar energy stands out among these sources due to its abundance and global accessibility. However, its weather-dependent and cyclical nature add inherent risks, making effective planning and management difficult. Soft computing technologies provide attractive solutions for modeling such systems, while machine learning and optimization techniques are gaining popularity in the solar energy industry. The current literature highlights the growing use of soft computing technologies, emphasizing their potential to address difficult challenges in solar energy systems. To effectively reap the benefits, these strategies must be seamlessly connected with emerging technologies like the Internet of Things (IoT), big data analytics, and cloud computing. This integration provides a unique opportunity to improve the scalability, flexibility, and efficiency of solar energy systems. Researchers can use these synergies to create intelligent, linked solar energy ecosystems capable of real-time optimization of energy production, delivery, and consumption. These technologies have the potential to transform the renewable energy environment, allowing for more resilient and sustainable energy infrastructures. Furthermore, as these technologies improve, there is a growing demand for trained experts to address associated cybersecurity problems, assuring the integrity and security of these sophisticated systems. Researchers may pave the road for a more sustainable and energy-efficient future by working collaboratively and using interdisciplinary methodologies.

Sentinel Enhanced Dengue Surveillance System - Puerto Rico, 2012-2022.

Dengue is the most prevalent mosquitoborne viral illness worldwide and is endemic in Puerto Rico. Dengue's clinical spectrum can range from mild, undifferentiated febrile illness to hemorrhagic manifestations, shock, multiorgan failure, and death in severe cases. The disease presentation is nonspecific; therefore, various other illnesses (e.g., arboviral and respiratory pathogens) can cause similar clinical symptoms. Enhanced surveillance is necessary to determine disease prevalence, to characterize the epidemiology of severe disease, and to evaluate diagnostic and treatment practices to improve patient outcomes. The Sentinel Enhanced Dengue Surveillance System (SEDSS) was established to monitor trends of dengue and dengue-like acute febrile illnesses (AFIs), characterize the clinical course of disease, and serve as an early warning system for viral infections with epidemic potential. May 2012-December 2022. SEDSS conducts enhanced surveillance for dengue and other relevant AFIs in Puerto Rico. This report includes aggregated data collected from May 2012 through December 2022. SEDSS was launched in May 2012 with patients with AFIs from five health care facilities enrolled. The facilities included two emergency departments in tertiary acute care hospitals in the San Juan-Caguas-Guaynabo metropolitan area and Ponce, two secondary acute care hospitals in Carolina and Guayama, and one outpatient acute care clinic in Ponce. Patients arriving at any SEDSS site were eligible for enrollment if they reported having fever within the past 7 days. During the Zika epidemic (June 2016-June 2018), patients were eligible for enrollment if they had either rash and conjunctivitis, rash and arthralgia, or fever. Eligibility was expanded in April 2020 to include reported cough or shortness of breath within the past 14 days. Blood, urine, nasopharyngeal, and oropharyngeal specimens were collected at enrollment from all participants who consented. Diagnostic testing for dengue virus (DENV) serotypes 1-4, chikungunya virus, Zika virus, influenza A and B viruses, SARS-CoV-2, and five other respiratory viruses was performed by the CDC laboratory in San Juan. During May 2012-December 2022, a total of 43,608 participants with diagnosed AFI were enrolled in SEDSS; a majority of participants (45.0%) were from Ponce. During the surveillance period, there were 1,432 confirmed or probable cases of dengue, 2,293 confirmed or probable cases of chikungunya, and 1,918 confirmed or probable cases of Zika. The epidemic curves of the three arboviruses indicate dengue is endemic; outbreaks of chikungunya and Zika were sporadic, with case counts peaking in late 2014 and 2016, respectively. The majority of commonly identified respiratory pathogens were influenza A virus (3,756), SARS-CoV-2 (1,586), human adenovirus (1,550), respiratory syncytial virus (1,489), influenza B virus (1,430), and human parainfluenza virus type 1 or 3 (1,401). A total of 5,502 participants had confirmed or probable arbovirus infection, 11,922 had confirmed respiratory virus infection, and 26,503 had AFI without any of the arboviruses or respiratory viruses examined. Dengue is endemic in Puerto Rico; however, incidence rates varied widely during the reporting period, with the last notable outbreak occurring during 2012-2013. DENV-1 was the predominant virus during the surveillance period; sporadic cases of DENV-4 also were reported. Puerto Rico experienced large outbreaks of chikungunya that peaked in 2014 and of Zika that peaked in 2016; few cases of both viruses have been reported since. Influenza A and respiratory syncytial virus seasonality patterns are distinct, with respiratory syncytial virus incidence typically reaching its annual peak a few weeks before influenza A. The emergence of SARS-CoV-2 led to a reduction in the circulation of other acute respiratory viruses. SEDSS is the only site-based enhanced surveillance system designed to gather information on AFI cases in Puerto Rico. This report illustrates that SEDSS can be adapted to detect dengue, Zika, chikungunya, COVID-19, and influenza outbreaks, along with other seasonal acute respiratory viruses, underscoring the importance of recognizing signs and symptoms of relevant diseases and understanding transmission dynamics among these viruses. This report also describes fluctuations in disease incidence, highlighting the value of active surveillance, testing for a panel of acute respiratory viruses, and the importance of flexible and responsive surveillance systems in addressing evolving public health challenges. Various vector control strategies and vaccines are being considered or implemented in Puerto Rico, and data from ongoing trials and SEDSS might be integrated to better understand epidemiologic factors underlying transmission and risk mitigation approaches. Data from SEDSS might guide sampling strategies and implementation of future trials to prevent arbovirus transmission, particularly during the expansion of SEDSS throughout the island to improve geographic representation.

Germination Predication to Access the Quality of Grains for Different Crops Using IoT and Machine Learning

The paper expounds on a advanced framework that consistently blends Counterfeit Insights (AI) and Web of Things (IoT) innovations to figure seed germination in rural settings. It underscores the noteworthiness of leveraging real-time information sourced from soil sensors nearby cutting-edge machine learning calculations to supply important bits of knowledge into the designs of edit germination. This imaginative framework is made with the essential objective of preparing ranchers with opportune and significant data, subsequently encouraging educated decision-making forms relating to water system procedures and asset assignment. Central to the system's engineering is its versatility, encouraged by a cloud-based stage that empowers consistent development and adjustment to shifting rural necessities. This guarantees not as it were the productive investigation of sensor- derived information but moreover permits for the customization of the system's highlights to suit the different needs of diverse rural settings. Subsequently, the system's flexibility loans itself to optimizing yields and cultivating feasible nourishment generation hones, subsequently contributing to the overarching objective of guaranteeing nourishment security and natural stewardship. Keywords— Smart System, Seed Germination Prediction, AI and IoT Integration, Agriculture, Machine Learning Models, Real-time Data, Crop Management, Scalable Cloud Platform, Customizable Design, Sustainable Food Production.

Проблемы современной сферы образования и ее влияние на экономику страны

The field of education is undergoing significant transformations in response to the evolving needs of society and the economy. In the face of rapid technological advancements and changes in the socio-economic environment, there is a need for updating the content of education to provide the younger generation with the opportunity to successfully adapt and compete in the labor market. The flexibility and responsiveness of the educational system to the changing demands of the modern world are crucial aspects of successfully addressing issues related to the field of education. It is important to create a flexible system capable of tracking current market requirements and offering new knowledge and skills for the future. Additionally, it is necessary to consider the individual characteristics of each learner to create comfortable conditions for their development. This article conducts an analysis of the aforementioned topic, examines changes in the modern educational system, and proposes solutions to the problematic issues in the field of education. In conclusion, the challenges facing modern education are multifaceted and require a comprehensive approach to address. By fostering flexibility, responsiveness, and inclusivity within the education system, countries can better prepare their citizens for the demands of the 21st-century economy. Strategic investments in education, coupled with ongoing research and innovation, are essential for ensuring the continued prosperity and competitiveness of nations in the global marketplace.

Research on the influence of flexible wheelset rotation effect on wheel rail contact force

PurposeUnder the high-speed operating conditions, the effects of wheelset elastic deformation on the wheel rail dynamic forces will become more notable compared to the low-speed condition. In order to meet different analysis requirements and selecting appropriate models to analyzing the wheel rail interaction, it is crucial to understand the influence of wheelset flexibility on the wheel-rail dynamics under different speeds and track excitations condition.Design/methodology/approachThe wheel rail contact points solving method and vehicle dynamics equations considering wheelset flexibility in the trajectory body coordinate system were investigated in this paper. As for the wheel-rail contact forces, which is a particular force element in vehicle multibody system, a method for calculating the Jacobian matrix of the wheel-rail contact force is proposed to better couple the wheel-rail contact force calculation with the vehicle dynamics response calculation. Based on the flexible wheelset modeling approach in this paper, two vehicle dynamic models considering the wheelset as both elastic and rigid bodies are established, two kinds of track excitations, namely normal measured track irregularities and short-wave irregularities are used, wheel-rail geometric contact characteristic and wheel-rail contact forces in both time and frequency domains are compared with the two models in order to study the influence of flexible wheelset rotation effect on wheel rail contact force.FindingsUnder normal track irregularity excitations, the amplitudes of vertical, longitudinal and lateral forces computed by the flexible wheelset model are smaller than those of the rigid wheelset model, and the virtual penetration and equivalent contact patch are also slightly smaller. For the flexible wheelset model, the wheel rail longitudinal and lateral creepages will also decrease. The higher the vehicle speed, the larger the differences in wheel-rail forces computed by the flexible and rigid wheelset model. Under track short-wave irregularity excitations, the vertical force amplitude computed by the flexible wheelset is also smaller than that of the rigid wheelset. However, unlike the excitation case of measured track irregularity, under short-wave excitations, for the speed within the range of 200 to 350 km/h, the difference in the amplitude of the vertical force between the flexible and rigid wheelset models gradually decreases as the speed increase. This is partly due to the contribution of wheelset’s elastic vibration under short-wave excitations. For low-frequency wheel-rail force analysis problems at speeds of 350 km/h and above, as well as high-frequency wheel-rail interaction analysis problems under various speed conditions, the flexible wheelset model will give results agrees better with the reality.Originality/valueThis study provides reference for the modeling method of the flexible wheelset and the coupling method of wheel-rail contact force to the vehicle multibody dynamics system. Furthermore, by comparative research, the influence of wheelset flexibility and rotation on wheel-rail dynamic behavior are obtained, which is useful to the application scope of rigid and flexible wheelset models.

Design and Implementation of a Hybrid-Driven Soft Robot

Currently, soft robots alone cannot obtain the same operating speed as rigid robots, while rigid robots are not safe enough for human-robot interaction. To address this problem, this paper describes a hybrid robot system that combines both rigid and flexible systems for unknown domain exploration. The system consists of a four-wheeled robot chassis and a cylindrical pneumatic soft actuator, and finally, a computer is used to coordinate and control both. The hardware of the robot system is designed, a bending motion model is proposed, and SOFA framework is used to carry out finite element simulation (FEM) to verify the reasonableness of the design; linear motion speeds of up to 0.5 m/s, higher than the existing soft robots investigated, were verified experimentally separately after carrying the new module, and steering ability was retained; and the robot carrying the navigation module is verified to have a certain map building and localization function through the construction of the simultaneous localization and mapping (SLAM) experimental platform. The hybrid robot introduced in this paper can move quickly on flat terrain and can use its soft part to avoid wear and tear.

Nanoscale Adhesion and Material Transfer at 2D MoS2-MoS2 Interfaces Elucidated by In Situ Transmission Electron Microscopy and Atomistic Simulations.

Low-dimensional materials, such as MoS2, hold promise for use in a host of emerging applications, including flexible, wearable sensors due to their unique electrical, thermal, optical, mechanical, and tribological properties. The implementation of such devices requires an understanding of adhesive phenomena at the interfaces between these materials. Here, we describe combined nanoscale in situ transmission electron microscopy (TEM)/atomic force microscopy (AFM) experiments and simulations measuring the work of adhesion (Wadh) between self-mated contacts of ultrathin nominally amorphous and nanocrystalline MoS2 films deposited on Si scanning probe tips. A customized TEM/AFM nanoindenter permitted high-resolution imaging and force measurements in situ. The Wadh values for nanocrystalline and nominally amorphous MoS2 were 604 ± 323 mJ/m2 and 932 ± 647 mJ/m2, respectively, significantly higher than previously reported values for mechanically exfoliated MoS2 single crystals. Closely matched molecular dynamics (MD) simulations show that these high values can be explained by bonding between the opposing surfaces at defects such as grain boundaries. Simulations show that as grain size decreases, the number of bonds formed, the Wadh and its variability all increase, further supporting that interfacial covalent bond formation causes high adhesion. In some cases, sliding between delaminated MoS2 flakes during separation is observed, which further increases the Wadh and the range of adhesive interaction. These results indicate that for low adhesion, the MoS2 grains should be large relative to the contact area to limit the opportunity for bonding, whereas small grains may be beneficial, where high adhesion is needed to prevent device delamination in flexible systems.

Adaptive observer based controls for a flexible wing system under unknown output disturbances

This paper considers a wing system under unknown output disturbances, references, distributed disturbances and boundary disturbances. These signals have unknown frequencies, amplitudes and phases, and are then supposed to be from an exosystem with an unknown matrix. In this sense, we firstly find the wing system merely under the references and output disturbances, for which the PDE observer can be easily designed based on the measurable outputs. Then, an adaptive observer is designed for a detectable exosystem so that the references have known coefficients and approximately known states. Adaptive observer based controls are then proposed for the closed-loop system so that the convergence of tracking error and the boundedness of the states are guaranteed. Two simulation examples are compared to show the robustness of the designed controls.

Optimizing 6G Network Slicing with the EvoNetSlice Model for Dynamic Resource Allocation and Real-Time QoS Management

This research paper focuses on thoroughly examining the challenges in 6G network slicing. To develop, evaluate performance characteristics for on-demand reallocation and instantaneously changeable QoS EvoNetSlice model. The study employs integrated evolutionary algorithms with artificial intelligence-enabled data analytics and multi-objective optimization to optimize network resources usage under minimum end-to-end delay, high transmission rates and optimal background data management. Firstly, the network resource allocation individuals should be based on the network traffic data, QoD (quality of demand) value for some applications and users’ behaviors. The performance degradation detection and quality of service (QoS) adaptation mechanism combined with a multi-layer objective fitness function for achieving good balance in conflict between conflicting objectives. Results indicate that EvoNetSlice improves the general efficiency of a particular network, adapts according to ever shifting requirements for QoS at any time and provides crucial statistics-focused data on network management. The importance of this work lies in developing the future 6G network’s technology. W the key issues, including resource optimization and real-time adaptation required to support modern 6G services, are considered by EvoNetSlice. Such an exploration is an essential element in developing flexible 6G systems that will define next-generation wireless communication.

Robust damping improvement against the vortex-induced vibration in flexible bridges using multiple tuned mass damper inerters

The tuned mass damper inerter (TMDI) is considered as one of countermeasures to mitigate the very-low-frequency vertical bending vortex-induced vibration (VIV) in flexible bridges. However, the control robustness of the TMDI against the system uncertainty is a serious concern due to the limited inerter span capacity. In this paper, the multiple tuned mass damper inerter (MTMDI) is used instead of identical TMDIs to provide a robust equivalent damping ratio against the uncertain VIV within the entire lock-in wind speed range. A design framework of the MTMDI considering the inerter span length is proposed based on a universal VIV model suitable for the fully closed, centrally slotted, and semi-closed box decks. In the framework, the fluctuation of VIV characteristics with the wind speed, the probability of occurrence of the VIV, and the uncertainties in VIV characteristics and deck dynamics are considered, simultaneously. Two objection functions are defined to focus on the maximizing the equivalent damper ratio and reducing the VIV mitigation failure, respectively. Finally, numerical analysis of a flexible bridge-MTMDI system subjected to the VIV is performed. The results show that the wind speed probability distribution plays a role of weighting coefficient in the MTMDI optimization. The choice of the objective function depends on the mass ratio of the MTMDI and the level of the system uncertainty. The well-optimized MTMDI achieved a more robust control result than the TMDI within the entire lock-in wind speed range.

Improved mountain gazelle optimizer based interactive distributed strategy to solving large scale OPF

This paper focuses on solving the multi-objective optimal power flow of large-scale power systems under critical loading margin stability with accuracy using a novel improved mountain gazelle optimizer (IMGO)-based flexible distributed strategy. Multi-shunt compensator-based flexible alternative current transmission systems (FACTS), such as SVC and STATCOM devices, are integrated at specified locations to exchange reactive power with the network. Several metaheuristic methods can solve the standard OPF related to small and medium test systems. However, by considering large-scale electric systems based on FACTS devices and renewable energy and by considering the operation under loading margin stability, the majority of these techniques fail to achieve a near-global solution because of the high dimension and nonlinearity of the problem to be solved. This study proposes the Multi-Objective OPF-Based Distributed Strategy (MO-OPFDS), a new planning strategy that optimizes individually and simultaneously various objective functions, in particular the total power loss (T∆P), and the total voltage deviation (T∆V). Standard MGO search is enhanced by automatically balancing exploration and exploitation throughout the search. The robustness of the proposed variant was validated on a large electric test system, the IEEE 118-Bus, and on the Algerian Network 114-Bus under normal conditions and at critical loading margin stability. The obtained results compared with several recent techniques clearly confirm the high performance of the proposed method in terms of solution accuracy and convergence behavior.

Proof in Dutch Administrative Law

The law of proof and evidence in Dutch administrative law is founded on a theory of free evidence. Over the years, evidential standards have been derived from general principles of sound administration, such as the duty of due care and the duty to give reasons. A flexible system of proof is the result, aptly tailored to the circumstances of the case. This article focuses on the dynamics of the law of proof and evidence in the Netherlands and aims to offer a perspective on future challenges and expected developments. It is argued that evidential norms have become more explicit and precise on the one hand, while at the same time being deformalised. Dutch administrative law courts are increasingly focusing on standards that offer citizens safeguards in fact finding. Evidential norms should increase the quality of fact finding, protect citizens from an over-intrusive administrative state and compensate for an inequality of arms. Over the past few years, courts have worked on effective options for litigants to adduce evidence in appeal. Most recently, the government has published a bill strengthening this evidentiary position by introducing a specific procedural instrument known as the ‘citizen loop’. These developments are bolstered by European case law, which asks for enhanced human rights protection and effective legal protection.