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BackgroundThe current study (1) examined links between daily stressors and inflammation and (2) tested whether negative emotion dynamics (emotional variability) is one pathway through which stressors are linked to inflammation.MethodA cross-sectional sample of 986 adults (aged 35-86 years, 57% female) from MIDUS reported daily stressor frequency and severity and negative emotions on 8 consecutive nights. Negative emotion variability (intraindividual standard deviation), controlling for overall mean level (intraindividual mean), was the focus of the current study. Interleukin-6 (IL-6) and C-reactive protein (CRP) were assayed from blood drawn at a clinic visit. Regression models adjusted for demographics, health factors, and the time between assessments.ResultsMore severe daily stressors were associated with higher CRP, but this effect was accounted for by covariates. More frequent daily stressors were associated with lower IL-6 and CRP. In follow-up analyses, significant interactions between stressor severity and frequency suggested that participants with lower stressor severity and higher stressor frequency had the lowest levels of IL-6 and CRP, whereas those with higher stressor severity had the highest levels of IL-6 and CRP, regardless of frequency. Daily stressor frequency and severity were positively associated with negative emotion variability, but variability was not linearly associated with inflammation and did not operate as a mediator.ConclusionAmong midlife and older adults, daily stressor frequency and severity may interact and synergistically associate with inflammatory markers, potentially due to these adults being advantaged in other ways related to lower inflammation, or in a pattern aligning with hormetic stress, where frequent but manageable stressors may yield physiological benefits, or both. Negative emotion variability does not operate as a mediator. Additional work is needed to reliably measure and test other emotion dynamic metrics that may contribute to inflammation.

Commentary to the Lecture “Moving the immovable: Climate change and the multiple tensions between mobility and immobility”, by Huub Dijstelbloem (this issue).

This paper gives an experimentally supported review and comparison of several indices based on the conventional K-means inertia criterion for determining the number of clusters, $K$ , in datasets, using the popular Silhouette width index as a benchmark. Our experiments involve a novel version of the Elbow index, defined using values of $K$ two or three steps apart. We also discuss alternative ways of computing the inertia and summarizing its values. Even though there are no overall winners in our experiments, some of our results are very conclusive and can be used as a guide for indices determining the number of clusters in K-means.

With the increasing proliferation of photovoltaic (PV) and wind power globally, frequency regulation by balancing generation and load in power systems is becoming increasingly difficult owing to reductions in dispatchable power and inertia. One countermeasure is autonomous load control, in which thermostatic loads and electric vehicle chargers quickly adjust the power consumption based on the grid frequency monitored by themselves without communication. However, testing the impact of such load controls on the frequency in actual power systems is too expensive. Therefore, a laboratory-scale isolated power system was prepared as a test bed to examine autonomous load control based on the rate of change of frequency (RoCoF) and the frequency deviation to cope with steep frequency fluctuations. Moreover, the experimental system was simulated numerically using MATLAB/Simulink. The experimental and simulation results are comparable, indicating that the simulation can be used to determine the total capacity and threshold when planning the introduction of autonomous control loads. The experimental and simulation results also show that frequency fluctuations can be mitigated by introducing autonomous control loads to the grid, and the response time can be improved by approximately 1 s by controlling the load based on the RoCoF.

Matrix converters (MC) have been considered for applications in renewable power generation and microgrids. However, similar to other power electronic converter-interfaced power generation systems, the MC-interfaced system cannot provide inertia or damping effect to support the grid’s frequency or voltage. To improve the inertia and damping effect of the MC-interfaced distributed generation system and realize the grid-friendly connection of new energy power generation, a virtual synchronous generator (VSG) control strategy suitable for the MC-interfaced system is proposed. Aiming at the problem that the system frequency in the traditional VSG cannot be restored to the nominal value after the load power fluctuations, the VSG secondary frequency control strategy is introduced. To ensure a smooth grid connection, a synchronization control strategy based on virtual power has been designed. An experimental validation platform was built and the experimental results verify the correctness and effectiveness of the proposed control strategies for a grid-forming MC.

This paper investigates the use of a battery energy storage system (BESS) to enhance the frequency response characteristics of a low-inertia power system following a disturbance or active power mismatch. A simple control strategy of the BESS is proposed to improve the inertia response and primary frequency response of the system. The effectiveness of the proposed control strategy is evaluated on two test systems, which have been modified by replacing some fossil fuel-based generators with solar photovoltaic (PV) systems to create low inertia systems. A BESS is then added to provide additional system inertia. The DigSILENT PowerFactory software is used to model these modified systems with the BESS and to generate the corresponding frequency response characteristics under various power imbalanced conditions. Simulation results indicate that the BESS, with the proposed control strategy, can improve the system rate-of-change of frequency (ROCOF), frequency nadir (minimum frequency), and final steady-state frequency. In the 3-machine system, replacing a traditional power plant with a solar PV farm decreases the frequency nadir from 49.34 Hz to 48.69 Hz following a sudden load increase of 60 MW. However, adding a 30 MW BESS improves the frequency nadir to 49.48 Hz, which is better than the original system. In the 4-machine system, replacing two traditional power plants with solar farms increases the initial ROCOF to 0.55 Hz/s, exceeding the acceptable limit of 0.50 Hz/s for a severe disturbance. However, incorporating a BESS reduces the initial ROCOF to 0.44 Hz/s.

Abstract In this paper, we prove strong convergence theorem of the general inertial Mann–Halpern algorithm for nonexpansive mappings in the setting of Hilbert spaces. We also prove weak convergence theorem of the general inertial Mann algorithm for k-strict pseudo-contractive mappings in the setting of Hilbert spaces. These convergence results extend and generalize some existing results in the literature. Finally, we provide examples to verify our main results.

The seed germination dynamics of Acacia nilotica, Bauhinia rufescens, Faidherbia albida , and Piliostigma reticulatum were investigated over 28 days. Seeds were pretreated with concentrated sulfuric acid. Determined germination parameters included germination energy, germination period, germination capacity, germination inertia, and viability loss. Seeds exposed to sulfuric acid for extended periods (30, 40, 50, and 60 min) exhibited a higher germination rate ( α = 0.05). For A. nilotica seeds, the 50 min acid treatment resulted in the highest germination energy of 85.5% and germination capacity of 89.5% ( P = 0.001); conversely, the 60-min treatment yielded the highest germination energy and capacity, both 96.5% ( P = 0.079), for P. reticulatum . In the case of B. rufescens , the 30-min treatment led to the highest germination energy of 93% and germination capacity of 88% ( P = 0.001). For F. albida, all acid treatments resulted in 100% for both germination energy and germination capacity ( P = 0.621). Viability losses for A. nilotica and P. reticulatum were higher (32 and 30%, respectively) than those for B. rufescens and F. albida , which were 19.5 and 6%, respectively ( P = 0.000). Generally, higher germination energy resulted in lower viability loss, dependent on the species. Analyses of germination inertia and viability loss suggest that seeds of A. nilotica and P. reticulatum possess a greater ability to survive in arid land climates than those of B. rufescens and F. albida. However, due to the advantage of lower viability loss, B. rufescens and F. albida should be preferred for the natural restoration of arid land ecosystems where seed availability is a major concern.

The generation of inverter-based renewable energy affects system frequency and is limited by frequency criteria. In a power system with two or more criteria, it is important to understand whether the frequency criteria are appropriate because these should not differ in terms of renewable energy generation for consistent power operation. This study proposes a method to evaluate the frequency criteria applied to the system operation data by determining the minimum level of inertia required for the latter according to the effect of renewable energy generation. The minimum level of inertia can be determined as the minimum inertia value that satisfies the frequency criteria when inertia and frequency regulating reserve change with the operation of the generator. The minimum level of inertia was determined by conducting a frequency simulation by applying two frequency criteria in Korea. The proposed methodology has been applied to 7080 operation data, when two maximum output generators are operating more than 1400 MW simultaneously, out of 23003 time-based data extracted from the Energy Management System (EMS). Further, from the results, the minimum level of inertia for the N-1 frequency criterion was higher than the generator N-2 frequency criterion. This result indicates that the N-1 frequency criterion is more conservative in terms of the accommodation of renewable energy than the N-2 frequency criterion and that renewable energy will be limited by the N-1 frequency criterion. An important finding of this study is that the two frequency criteria in South Korea are applied differently in terms of the minimum level of inertia.

In the turbulent environment of today's world, if a company or organization does not have the ability to adapt to global changes and developments, it is doomed to collapse and destruction. Therefore, companies and organizations, if they want their survival not to be threatened, should accept creativity and innovation as the main keywords of their main strategies, programs and policies. Therefore, the current research was conducted with the aim of knowing and understanding the inertia of innovation in knowledge-based companies. This research is based on mixed research and is qualitative and quantitative, which is applied in terms of purpose and descriptive survey in terms of nature and method. The statistical population of the research is managers and professors of knowledge-based companies, whose opinions are examined in the qualitative and quantitative part of the research as experts. The members of the statistical sample of this research were selected by purposive sampling method. In the qualitative part of the research, the data collection tool is a semi-structured interview, the validity and reliability of which was confirmed using the CVR coefficient and intra-coder and inter-coder tests. The tool for collecting information in the quantitative part is a questionnaire whose validity and reliability were confirmed using content validity and retesting. In the qualitative part, the qualitative data obtained from the interview were analyzed using Atlas.ti software and the coding method, and the factors causing innovation inertia in Iranian knowledge-based companies were identified. In addition, in the quantitative part of the research, using the FCM method, the factors that create and the consequences of innovation inertia in Iran's knowledge-based companies are prioritized, and the most important factors that create and the consequences of innovation inertia in knowledge-based companies are identified. The results of the research show that the rule of the imitation culture instead of the culture of innovation, suffering from intellectual arthritis syndrome, fear and conservative spirit, intellectual freezing and using previous experiences in solving new problems are the most important factors that cause the inertia of innovation, as well as four factors. Among other things, the reduction of efficiency and productivity, weakness in learning and problem solving, making unfavorable decisions and the risk of the organization's survival, and the phenomenon of strategic blockage and impasse are very important consequences of the inertia of innovation in knowledge-based companies.

We argue that the fundamental assertion underlying Mach's critique of Newton's first law is that inertial motion is not motion in the absence of causes; rather, it is motion whose cause lies in some homogeneous aspect of the environment. We distinguish this formal requirement (Mach's principle) from two hypotheses which Mach considers concerning the origin of inertia: that the distant stars play (1) a merely "collateral" or (2) a "fundamental" role in the causal determination of inertial motion. In his later writings, Mach deliberately avoids referring to the concept of causation, and indeed, this has made the interpretation of Mach's principle a subject of widespread controversy. However, in his earlier writings, the substance of Mach's critique is less ambiguously expressed. Therefore, close attention is given to Mach's early writings and the evolution of his thought. Various accounts in the secondary literature on Mach's principle, in particular those of Norton and DiSalle, are assessed on this basis. We end with a defence of the Machian status and legitimacy of the early Einstein's research program. [ABSTRACT FROM AUTHOR]

Entanglement witnesses (EWs) are a fundamental tool for the detection of entanglement. We investigate the inertia of bipartite EWs constructed by the partial transpose of NPT states. Furthermore, we find out most of the inertia of the partial transpose of the two-qutrit bipartite NPT states. As an application, we extend our results to high-dimensional states. [ABSTRACT FROM AUTHOR]

The complex adjacency matrix A C (G) for a multidigraph G is introduced in Barik and Sahoo (AKCE Int J Graphs Comb 17(1):466–479, 2020). We study the rank of multidigraphs corresponding to the complex adjacency matrix and call it A C -rank. It is known that a connected graph G has rank 2 if and only if G is a complete bipartite graph, and has rank 3 if and only if it is a complete tripartite graph (Cheng in Electron J Linear Algebra 16:60–67, 2007). We observe that these results hold as special cases for multidigraphs but are not sufficient. In this article, we characterize all multidigraphs with A C -rank 2 and 3, respectively. [ABSTRACT FROM AUTHOR]

Since renewable energy sources (RES) have almost little inertia, an increase in their electricity might harm the power system's ability to run steadily and dependably. Numerous solutions to the issue mentioned above are offered. This paper aims to assess the technological possibility of using energy storage system (ESS) devices built from batteries and supercapacitors to enhance the interia response of sources in microgrids with a large amount of PV power penetration. The microgrid's inertia was altered by varying the penetration level of RES. To obtain a rigid microgrid, batteries and supercapacitors are suggested in this study to enhance frequency stability and droop control is utilized to complete this assessment. The model of the on-grid power network was designed using Simulink in MATLAB to evaluate the high level of RES penetration impact on the frequency stability of the system. Results verify that the microgrid stiffness is significantly enhanced when the suggested storage elements are incorporated. The findings show that the rate of change of frequency (RoCoF) is reduced when the size of the ESS increases and vice versa. The supercapacitor energy storage system (SCESS) can increase the stability of the system's frequency more effectively than the battery energy storage systems (BESS) with a slower time response. [ABSTRACT FROM AUTHOR]

Under-frequency load shedding (UFLS) schemes are the latest safety measures applied for safeguarding the integrity of the grid against abrupt frequency imbalances. The overall inertia of electrical power systems is expected to decrease with an increased penetration of renewable energy as well as elements connected through power electronic interfaces. However, voltage source converter-based high voltage direct current (VSC-HVDC) links can provide virtual inertia through a control loop that allows for a reaction to occur at certain frequency fluctuations. This paper evaluates a UFLS scheme that considers the injection of virtual inertia through a VSC-HVDC link. A genetic algorithm (GA) is used to determine the location of the UFLS relays, the activation threshold of each stage, the delay time and the percentage of load shedding at each stage. It was found that the virtual inertia causes the nadir to delay and sometimes reach a greater depth. Furthermore, the implemented GA approximates the frequency response to the limits set with the constraints, reducing the load shedding but achieving a steeper nadir and a lower steady-state frequency level than traditional UFLS. The simulations were performed using the IEEE 39-bus test system. [ABSTRACT FROM AUTHOR]

In this study, we investigate the relations between a multiple partitioned linear model and its correctly-reduced models. We consider the comparison problem of covariance matrices of the best linear unbiased predictors (BLUPs) of all unknown vectors including partial parameters under these models by using the block matrix rank and inertia formulas. We derive various inequalities and equalities for covariance matrices of BLUPs under some general assumptions. Also, results for special cases are given. [ABSTRACT FROM AUTHOR]

We introduce an axiomatization of entropy that generates, as special cases, novel entropy types. These entropies generalize Shannon's entropy and allow the introduction of entropy for partitions of sets of objects located in metric spaces, and for partitions of sets of vertices in undirected graphs. Corresponding metrics on the sets of partitions are introduced. Also, we hint to applications of these metrics for evaluation of clustering quality. [ABSTRACT FROM AUTHOR]

Background: Managing the transition of a health system (HS) from a centralised to a decentralised model has been touted as a panacea to the complex challenges in developing countries like Malawi. However, recent studies have demonstrated that decentralisation of the HS has had mixed effects in service provision with more dominant negative outcomes than positive results. The aim of this study was to develop a substantive grounded theory (GT) that elaborates on how activities of central decision-makers and local healthcare mangers shape the process of shifting the HS to a decentralised model in Machinga, Malawi. Methods: The study was qualitative in nature and employed the Straussian version of GT. Some participants were interviewed twice, and a total of 36 semi-structured interviews were conducted with 25 purposively selected participants using an interview guide. The interviews were conducted at the headquarters of the Ministry of Health (MoH) and other ministries and agencies, and in Machinga District. Data were analysed using open, axial, and selective coding processes of the GT methodology; and the conditional matrix and paradigm model were used as data analysis tools. Results: The findings of this study revealed seven different activities, forming two opposing and interactional subprocesses of enabling and impeding patterns that derailed the decentralisation drive. The study generated a GT labelled "decentralisation of the HS derailed by organisational inertia," which elaborates that decentralisation of the HS produced mixed results with more predominant negative outcomes than positive effects due to resistance at the upper organisational echelons and members of the District Health Management Team (DHMT). Conclusion: This article concludes that organisational inertia at the personal and strategic levels of leadership entrusted with decentralising the HS in Malawi, contributed immensely to the derailment of shifting the HS from the centralised to the decentralised model of health service provision. [ABSTRACT FROM AUTHOR]

As cooperatives become a crucial part of our society's repository of solutions for addressing the sustainability challenges, the very emergence of cooperatives continues to puzzle scholars. In this study we address a central concern for both organizational scholars and sustainability advocates, i.e. where and under which conditions cooperatives emerge as an alternative form to corporations. Building on organizational ecology theories, we argue that the varying organizational characteristics within local incumbent forms constitute an additional layer to explain cooperatives' emergence, above and beyond the known effects of community characteristics and incumbents' aggregated density (or capacity). Our analysis of a unique data set of German energy cooperatives between 2003 and 2010 support our hypotheses. Our results show that energy cooperatives are more likely to be founded where incumbent utilities have higher average age and greater size diversity, because age-related inertia and lack of competition among incumbents of diverse size limit their adaptability towards serving the new market demand for renewable energy. [ABSTRACT FROM AUTHOR]

Let r be any real number and for any n let p1,...., pn be distinct positive numbers. A Kwong matrix is the n x n matrix whose (i, j) entry is (pri +prj)/(pi +pj). We determine the signatures of eigenvalues of all such matrices(The corresponding problem for the family of Loewner matrices [(pri +prj)/(pi - pj)] has been solved earlier. [ABSTRACT FROM AUTHOR]

When studying the properties of candidate materials for fuel elements of designed nuclear power plants, the most important role is played by conducting reactor experiments. To obtain information about the temperature change of samples of experimental fuel rods in real time, they are instrumented with thermocouples. The correctness of the performed measurements depends on various factors, an important one of which is the quality of the thermocouple seal on the surface of the test sample. As part of the preparation for conducting fuel experiments at the IR-8 reactor of the National Research Center Kurchatov Institute, it is necessary to conduct pre-reactor tests of experimental fuel rods and their prototypes. This article discusses a computational and experimental method, the use of which makes it possible to obtain the inertia of thermocouples attached to the test object in various ways. Requirements for the inertia of thermocouples used during testing are determined on the basis of the parameters of the considered nonstationary processes. Comparison of the total inertias of the fixed thermocouples and the experimental prototype can also be used to draw conclusions about the quality of the embedment. To test the proposed method for determining inertia, a special laboratory rig was created on which experimental values were obtained for thermocouples attached to the surface of the sample in two ways. A description and results of testing an analytical model for determining the error in measuring the sample temperature using thermocouples are provided. The possibilities of using the developed computational and experimental method in preparing reactor research of experimental fuel rods are considered. [ABSTRACT FROM AUTHOR]

Human–robot interaction is of the utmost importance as it enables seamless collaboration and communication between humans and robots, leading to enhanced productivity and efficiency. It involves gathering data from humans, transmitting the data to a robot for execution, and providing feedback to the human. To perform complex tasks, such as robotic grasping and manipulation, which require both human intelligence and robotic capabilities, effective interaction modes are required. To address this issue, we use a wearable glove to collect relevant data from a human demonstrator for improved human–robot interaction. Accelerometer, pressure, and flexi sensors were embedded in the wearable glove to measure motion and force information for handling objects of different sizes, materials, and conditions. A machine learning algorithm is proposed to recognize grasp orientation and position, based on the multi-sensor fusion method. [ABSTRACT FROM AUTHOR]

In this paper, we prove strong convergence theorem of the general inertial Mann–Halpern algorithm for nonexpansive mappings in the setting of Hilbert spaces. We also prove weak convergence theorem of the general inertial Mann algorithm for k-strict pseudo-contractive mappings in the setting of Hilbert spaces. These convergence results extend and generalize some existing results in the literature. Finally, we provide examples to verify our main results. [ABSTRACT FROM AUTHOR]

In the present study an effort-sharing approach based on Inertia and Capability principles is proposed to assess European Union (EU27) carbon budget distribution among the Member States. This is done within the context of achieving the Green Deal objective and EU27 carbon neutrality by 2050. An in-depth analysis is carried out about the role of Economic Decoupling embedded in the Capability principle to evaluate the correlation between the expected increase of economic production and the level of carbon intensity in the Member States. The study proposes a simple mathematical model as a policy tool to assess and redistribute Member States' carbon budgets as frequently as necessary to encourage progress or overcome the difficulties each Member State may face during the decarbonization pathways. [ABSTRACT FROM AUTHOR]

This research aims to clarify the core attributes of travel photography service, and how it may be possible to cultivate tourist loyalty to this service when travelling to the next destination. A mixed method with two studies was conducted to answer these questions. Study 1 adopted semi-structured interviews and thematic analysis to identify the key variables and their potential relations. The results showed that co-creation experience in travel photography was mainly composed of sense seeking, multi-actor interaction, and active participation, which played an extremely important role in tourists' cognitive memory, service outcome evaluation, and future travel decision-making. To further verify the relationship between variables, study 2 used a survey to explore the formative mechanism and boundary conditions of the co-creation experience on tourist repurchase intention. The results indicated the co-creation experience was positively associated with repurchase intention. Memory recollection and photo satisfaction both mediated this relationship. Inertia positively moderated the relationships between co-creation experience, memory recollection and photo satisfaction on repurchase intention. These effects were stronger when individual inertia was high. This study also provides practical insights into how it may be possible to cultivate travel service loyalty in destination marketing. [ABSTRACT FROM AUTHOR]

The installation of battery energy storage systems (BESSs) with various shapes and capacities is increasing due to the continuously rising demand for renewable energy. To prepare for potential accidents, a study was conducted to select the optimal location for installing an input BESS in terms of frequency stability when the index assumes the backup input of the BESS. This study builds on the premise that installing a BESS on a bus in an area where active power absorption and transmission are the most active can significantly contribute to increasing the frequency recovery of the power system. Based on this premise, the magnitude of the active power flow and the proportional characteristics of the phase difference between buses were mathematically confirmed. This study also calculated the effective power sensitivity index of a bus with 13 FR-ESSs installed in a domestic system and reviewed the frequency output by establishing a table for each failure scenario. The results indicated that the effect of frequency rise can be estimated at the level of tidal current calculation. Thus, the study suggested a direction for subsequent studies to improve the sensitivity index. [ABSTRACT FROM AUTHOR]

In order to ensure the sustainable development of energy, the development of new power systems with a high penetration of renewable energy has become a key research direction in the field of power systems. This paper studies the system frequency response process and key indicators from the perspective of high-penetration renewable power systems and proposes an inertia and primary frequency response requirement assessment method for power system planning under high renewable penetration. First, by analyzing the frequency dynamic response process, the key parameters affecting frequency stability are determined, and the evolution trend of system inertia with increasing renewable penetration is analyzed. Second, based on the real-system data, the inertia and primary frequency response parameters for each generator are obtained. With the planning generation mix and load as the goal, whether the synchronous generators in the target system can meet the frequency stability requirements is determined. Finally, with the system inertia demand under the maximum rate of change of frequency (RoCoF) constraint as the starting point, we iteratively increase inertia and the primary frequency response capacity until the minimum matching configuration is found. The simulation results verify the correctness of the proposed assessment method. This method considers various processes in frequency response and multiple influencing factors, providing a practical evaluation tool for the inertia and primary frequency response requirements of high-penetration renewable power systems. [ABSTRACT FROM AUTHOR]

To reduce the influence of the rough airport pavement on the wheel-holding mechanism of tractors during traction, a vibration isolation device should be installed between the wheel-holding mechanism and the car body. Taking displacement transmissibility as the evaluation index of vibration isolation performance and random pavement function as excitation, this paper analyzes the vibration characteristics of the wheel-holding mechanism after adding inertial isolation device. It then compares the influences of spring stiffness, damping coefficient and inertial coefficient on the vibration isolation performance of the system. The results show that the average displacement transmissibility of traditional vibration isolation device and inertial vibration isolation device reaches 71.45% and 65.23% respectively. The increase of spring stiflness boosts the resonance frequency and anti- resonance frequency of the system. When the damping coefficient increases, the vibration transmission at resonance frequency decreases while the vibration isolation effect at anti-resonance frequency decreases. Higher inertia coefficient resulls in lower resonance frequency and anti-resonance frequency and wider vibration isolation frequency band. But the vibration isolation performance at high frequency tends to decline. Therefore, when the anti-resonance frequency is slightly lower than the working vibration frequency of the car body, the inertial vibration isolation device delivers outstanding performances in vibration isolation. Finally, our orthogonal test reveals the inertia coefficient exerts the biggest impact on the anti-resonance frequency point. [ABSTRACT FROM AUTHOR]

The data presented in this paper are related to the paper entitled “Optimal Estimation of Under-Frequency Load Shedding Scheme Parameters by Considering Virtual Inertia Injection”, available in the Energies journal. Here, data are included to show the results of an Under-Frequency Load Shedding (UFLS) scheme that considers the injection of virtual inertia by a VSC-HVDC link. The data obtained in six cases which were considered and analyzed are shown. In this paper, each case represents a different frequency response configuration in the event of generation loss, taking into account the presence or absence of a VSC-HVDC link, traditional and optimized UFLS schemes, as well as the injection of virtual inertia by the VSC-HVDC link. Data for each example contain the state of the relay, threshold, position in every delay, load shed, and relay configuration parameters. Data were obtained through Digsilent Power Factory and Python simulations. The purpose of this dataset is so that other researchers can reproduce the results reported in our paper.

This paper presents a comprehensive assessment of the large-scale deployment of hydropower on the provision of frequency regulation services, when equipped with the extended flexibility solutions being developed and/or tested within the scope of the XFLEX HYDRO project. The current analysis is performed on the Iberian Peninsula (IP) power grid considering its interconnection to the Continental Europe (CE) system, since this power system zone is expected to have the most severe frequency transient behaviour in future scenarios with increased shares of variable renewable energies. For this purpose, prospective scenarios with increased shares of time variable renewable generation were identified and analysed. To assess the impacts of the hydropower flexibility solutions on frequency dynamics after a major active power loss, extensive time domain simulations were performed of the power system, including reliable reduced order dynamic models for the hydropower flexibility solutions under evaluation. This research assesses the effects of synchronous and synthetic inertia, and of the Frequency Containment Reserve (FCR) and Fast Frequency Response (FFR) services as specified in European grid codes. The main findings highlight the potential of hydropower inertia and of adopting a variable speed technology for enhancing frequency stability, while contribute to better understand the role of hydropower plants in future power systems.

The progressive substitution of conventional synchronous generation for renewable-based generation imposes a series of challenges in many aspects of modern power systems, among which are the issues related to the low rotational inertia systems. Rotational inertia and the kinetic energy stored in the rotating masses in the power system play a fundamental role in the operation of power systems as it represents in some sort the ability of the system to withstand imbalances between generation and demand. Therefore, transmission system operators (TSOs) need tools to forecast the inertia or the kinetic energy available in the systems in the very short term (from minutes to hours) in order to take appropriate actions if the values fall below the one that ensures secure operation. This paper proposes a methodology based on machine learning (ML) techniques for short-term kinetic energy forecasting available in power systems; it focuses on the length of the moving window, which allows for obtaining a balance between the historical information needed and the horizon of forecasting. The proposed methodology aims to be as flexible as possible to apply to any power system, regardless of the data available and the software used. To illustrate the proposed methodology, time series of the kinetic energy recorded in the Nordic Power System (NPS) has been used as a case study. The results show that Linear Regression (LR) is the most suitable method for a time horizon of one hour due to its high accuracy-to-simplicity ratio, while Long Short-Term Memory (LSTM) is the most accurate for a forecasting horizon of four hours. Experimental assessment has been carried out using Typhoon HIL-404 simulator, verifying that both algorithms are suitable for real-time simulation.

IntroductionThe study explores the influence of Status Quo Bias theory constructs and the mediating role of inertia on individuals' resistance in making sustainable green home investment decisions among Indian homeowners and prospective homebuyers.MethodsA structured questionnaire was administered to 404 participants, and data analysis was performed using Partial Least Squares Structured Equation Modeling (PLS SEM).ResultsThe findings indicate that factors such as loss aversion, transition costs, adherence to social norms, and self-efficacy to change significantly contribute to individuals' resistance to green home investments. Inertia further amplifies the relationship between transition costs, social norms, and self-efficacy to change, but does not mediate the impact of loss aversion.DiscussionThis study is valuable for enhancing our understanding of biases in decision-making processes. To combat this resistance, it is crucial to provide clear information about the benefits of green home upgrades and offer incentives that reduce perceived costs and risks. This research sheds new light on the influence of status quo bias and inertia specifically within the context of green home investment decisions, addressing contemporary concerns for environmental sustainability and the increasing importance of such decisions in today's world.

Fluid flow in deformable fractures is important to many applications including hydraulic stimulation. Fracture flow simulations typically rely on the Poiseuille flow model which presumes laminar quasi‐steady‐state flow conditions with negligible inertia. The high flow rates involved in industrial applications bring these assumptions into question. The GG22 flow model is a new method to capture inertial effects and turbulent flow phenomena with a moderate increase in computational complexity. Here we develop and verify the first hydro‐mechanically coupled finite element – finite volume model for fracture flow which uses the GG22 model. We use the model to examine fracture flow between oscillating elastic plates and show that inertia may elicit phase‐shifts in the fluid response, larger fluid pressures and rock mass stresses, and induce wave‐like behaviour even in a quasi‐static rock mass. We then apply the model to hydraulic stimulation of a cemented fracture in both the viscous and toughness dominant propagation regimes and examine the influence of inertia and turbulence compared to Poiseuille flow. We demonstrate that inertial effects due to the variation of aperture are negligible in two‐dimensional KGD‐like fractures with constant injection rates. If the flow rates are large enough to invoke turbulent flow behaviour, then significantly different fracture propagation behaviour is observed. The modelling established in this article will serve as the basis to examine the role of inertia and turbulence in axisymmetrical radial fractures and dynamic stimulation with pressure pulsing where we expect the role of inertia to be more significant. [ABSTRACT FROM AUTHOR]

The seed germination dynamics of Acacia nilotica, Bauhinia rufescens, Faidherbia albida, and Piliostigma reticulatum were investigated over 28 days. Seeds were pretreated with concentrated sulfuric acid. Determined germination parameters included germination energy, germination period, germination capacity, germination inertia, and viability loss. Seeds exposed to sulfuric acid for extended periods (30, 40, 50, and 60 min) exhibited a higher germination rate (α = 0.05). For A. nilotica seeds, the 50 min acid treatment resulted in the highest germination energy of 85.5% and germination capacity of 89.5% (P = 0.001); conversely, the 60-min treatment yielded the highest germination energy and capacity, both 96.5% (P = 0.079), for P. reticulatum. In the case of B. rufescens, the 30-min treatment led to the highest germination energy of 93% and germination capacity of 88% (P = 0.001). For F. albida, all acid treatments resulted in 100% for both germination energy and germination capacity (P = 0.621). Viability losses for A. nilotica and P. reticulatum were higher (32 and 30%, respectively) than those for B. rufescens and F. albida, which were 19.5 and 6%, respectively (P = 0.000). Generally, higher germination energy resulted in lower viability loss, dependent on the species. Analyses of germination inertia and viability loss suggest that seeds of A. nilotica and P. reticulatum possess a greater ability to survive in arid land climates than those of B. rufescens and F. albida. However, due to the advantage of lower viability loss, B. rufescens and F. albida should be preferred for the natural restoration of arid land ecosystems where seed availability is a major concern. [ABSTRACT FROM AUTHOR]

Getting 'stuck', literally and figuratively, is a common experience for autistic people. Literally 'stuck' means exhibiting limited response initiation due to immobility with tense muscles and inability to move. Figuratively 'stuck' means loneliness, passivity or captivity in activities that do not offer long-term satisfaction. To further conceptualize this complex phenomenon of limited response initiation in autistic individuals, we performed qualitative interviews and focus groups with autistic people and their family members, followed by brainstorm sessions and a Delphi study with input from a larger panel of experts from multiple backgrounds. We aimed to co-create the outline of an integrative approach to support autistic people in moving away from this 'stuck state' to more flexible, limber 'supple states' in order to live freer, more meaningful, satisfying and peaceful lives. Over time, in interaction with all participants, our shared insight grew. Based on this, we here stipulate a conceptual framework, in which the described 'stuck state' at the microlevel of the muscles/behavior of one individual, probably is caused by feeling/being 'stuck' or 'cramped' at several overarching (i.e., meso and macro) levels. For instance, stuck in relationships with unhealthy dynamics, stuck at home creating short-term calm, trance-like states (e.g., gaming), stuck at an educational level that might fit the individuals' current social-emotional state rather than their potential cognitive level, stuck in a job that pays the bills but does not feel meaningful, nor contributes to a satisfying life with opportunities for personal development. Stuck in a mental/public health care system where ever ongoing changes in policies hinder sustained support to suit care-needs. Stuck in a regulated societal system making it likely to repeatedly get stuck. Is this phenomenon specific to autism? Formally we have only conducted interviews with this population, but in another smaller, related project we also spoke to people from the general population with careers that are considered successful in the general society. These people actually voiced similar experiences. Therefore, we hypothesize that this numbing state of being or feeling 'stuck' may be a prevalent phenomenon that needs to be addressed. In this article, we discuss several types of interventive approaches (i.e., language-based talking therapies, affective experiential expressive therapies, physical therapies and systemic therapies), prevention as well as intervention programs, directed at different primary stakeholders, that can complement and enrich each other in an integrative policy, that leads to tailor-made, personalized trajectories of interdisciplinary support to enable people to live satisfying, meaningful, dignified and peaceful lives. [ABSTRACT FROM AUTHOR]

The instability of an incompressible boundary layer on a compliant plate with respect to inviscid perturbations in the limit of high Reynolds numbers is analyzed using triple-deck theory. It is shown that unstable inviscid perturbations can exist only if the inertia and/or damping of the plate are taken into account. A twofold role of damping is revealed: it suppresses instability under certain conditions, while leading to its generation under other conditions. [ABSTRACT FROM AUTHOR]

We present novel evidence from a large panel of UK consumers who receive personalized reminders from a specialist price-comparison website about the precise amount they could save by switching to their best-suited alternative mobile telephony plan. We document three phenomena. First, even self-registered consumers with positive savings exhibit inertia. Second, we show that being informed about potential savings has a positive and significant effect on switching. Third, controlling for savings, the effect of incurring overage payments is significant and similar in magnitude to the effect of savings: paying an amount that exceeds the recurrent monthly fee weighs more on the switching decision than being informed that one can save that same amount by switching to a less inclusive plan. We interpret this asymmetric reaction on switching behavior as potential evidence of loss aversion. In other words, when facing complex and recurrent tariff plan choices, consumers care about savings but also seem to be willing to pay upfront fees in order to get "peace of mind". [ABSTRACT FROM AUTHOR]

In studies of dynamic stability and power quality, it is necessary to know the values of the mechanical parameters determining the transient response of wind turbines. Their exact values are not as decisive as the power curve, but an inaccurate estimate can distort or even invalidate the simulation results. From a review of the literature, it has been found that, despite their importance, the values of inertia, stiffness and damping are hardly available for any turbine model. Another detected problem is the lack of confidence in the data origin. This article aims to solve the issue of the scarcity and unreliability of data on inertia, and gathers the information found on the remaining mechanical parameters. Available blade inertia values in kg · m 2 are presented. Special treatment has been given to those providing the mass distribution along the blade span, for which the provided values of inertia have been compared with those obtained numerically, showing good matching. With this, different reliable relations are obtained that allow for the calculation of the turbine rotor inertia, based on the mass and length of the blade. When the center of gravity is also available, a very correlated expression ( r 2 = 0.975 ) is provided to obtain the inertia. The references to the stiffness and damping constant of the drive train, which are even more rare, will also be presented. In addition, the study includes a revision of gearboxes, generators and blade weight, according to their IEC-class and material. [ABSTRACT FROM AUTHOR]

The integration of power electronics-interconnected generation systems to the grid has fostered a significant number of concerns on power system operations, particularly on the displacement of synchronous generators that leads to a reduction in the grid's overall inertia and frequency response. These concerns have raised a significant amount of state-of-the-art mathematical proposals on how to estimate system inertia; however, the majority of the proposals do not differentiate generator inertia from load inertia. When inertia prediction for control room applications is required in real-time, the current state-of-the-art proposals use the inertia of generators as a proxy for a minimum, overall inertia estimate, counting the number of units committed in real-time and adding up their inertia. However, as dynamic conditions are becoming challenging with the integration of power electronics-interconnected generation systems, it is important to quantify the amount of inertia from the loads, for which the state-of-the-art proposals present very limited advancement, particularly in applications with real data. This work presents a set of recorded actual events in the Chilean power system to estimate the contribution of loads to inertia and frequency response to assess whether the loads have a significant role in frequency stability. The contribution of this work is as follows: first, reporting real data of a power system from the PMU and SCADA systems that are usually classified as not public; and, second, to derive a conclusion from the data to assess the role of loads in frequency stability in a real case. [ABSTRACT FROM AUTHOR]

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Copyright of Electric Power Automation Equipment / Dianli Zidonghua Shebei is the property of Electric Power Automation Equipment Press and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

ABSTRACT This paper is the history of how the theory of inertial inflation was developed in Brazil in the early 1980s, when inflation was very high, much higher than the stagflation that happened in the United States in the previous decade. Perhaps this fact explains why the theory was formulated in Brazil and not in the United States. The main papers and the book that defined the new theory are duly referred. And the author, that in the 1980s and 1990s was a political actor, also tells the history of the application of the theory, the failures and successes.