Output Line Research Articles

Interfacial Polarization Control Engineering and Ferroelectric PZT/Graphene Heterostructure Integrated Application.

Integration and miniaturization are the inevitable trends in the development of electronic devices. PZT and graphene are typical ferroelectric and carbon-based materials, respectively, which have been widely used in various fields. Achieving high-quality PZT/graphene heterogeneous integration and systematically studying its electrical properties is of great significance. In this work, we reported the characterization of a PZT film based on the sol-gel method. Additionally, the thickness of the PZT film was pushed to the limit size (~100 nm) by optimizing the process. The test results, including the remnant and leakage current, show that the PZT film is a reliable and suitable platform for further graphene-integrated applications. The non-destructive regulation of the electrical properties of graphene has been studied based on a domain-polarized substrate and strain-polarized substrate. The domain structures in the PZT film exhibit different geometric structures with ~0.3 V surface potential. The I-V output curves of graphene integrated on the surface of the PZT film exhibited obvious rectification characteristics because of p/n-doping tuned by an interfacial polarized electric field. In contrast, a ~100 nm thick PZT film makes it easy to acquire a larger strain gradient for flexural potential. The tested results also show a rectification phenomenon, which is similar to domain polarization substrate regulation. Considering the difficulty of measuring the flexural potential, the work might provide a new approach to assessing the flexural polarized regulation effect. A thinner ferroelectric film/graphene heterojunction and the polarized regulation of graphene will provide a platform for promoting low-dimension film-integrated applications.

Transcranial magnetic stimulation input-output curve slope differences suggest variation in recruitment across muscle representations in primary motor cortex.

Measurement of the input-output (IO) curves of motor evoked potentials (MEPs) elicited by transcranial magnetic stimulation (TMS) can be used to assess corticospinal excitability and motor recruitment. While IO curves have been used to study disease and pharmacology, few studies have compared the IO curves across the body. This study sought to characterize IO curve parameters across the dominant and non-dominant sides of upper and lower limbs in healthy participants. Laterality preferences were assessed in eight healthy participants and IO curves were measured bilaterally for the first dorsal interosseous (FDI), biceps brachii (BB), and tibialis anterior (TA) muscles. Results show that FDI has lower motor threshold than BB which is, in turn, lower than TA. In addition, both BB and TA have markedly shallower logarithmic IO curve slopes from small to large MEP responses than FDI. After normalizing these slopes by their midpoints to account for differences in motor thresholds, which could result from geometric factors such as the target depth, large differences in logarithmic slopes remain present between all three muscles. The differences in slopes between the muscles could not be explained by differences in normalized IO curve spreads, which relate to the extent of the cortical representation and were comparable across the muscles. The IO curve differences therefore suggest muscle-dependent variations in TMS-evoked recruitment across the primary motor cortex, which should be considered when utilizing TMS-evoked MEPs to study disease states and treatment effects.

Effect of Thickness and Thermal Treatment on the Electrical Performance of 2D MoS2 Monolayer and Multilayer Field-Effect Transistors

We deposited high-quality molybdenum disulfide (MoS2) monolayer and multilayer crystals on SiO2/Si substrates, by means of a chemical vapor deposition (CVD) process at atmospheric pressure. Notably, NaCl salt was used as component of the precursors to assist the growth of MoS2 crystals, which were intended for use as the active channel layer in the fabrication of field-effect transistors (FETs). The resulting MoS2 crystals from this CVD process were analyzed by optical, scanning electron, and atomic force microscopies, and by Raman and photoluminescence spectroscopies. The optical images and the micrographs obtained by SEM revealed the formation of dispersed MoS2 crystals with a triangular shape all over the SiO2 surface. The thickness of the MoS2 crystals, analyzed by atomic force microscopy, showed minimum values of around 0.7 nm, confirming the formation of monolayers. Additionally, multilayers with larger thickness were also identified. The Raman and photoluminescence spectra of the MoS2 crystals corroborated the formation of single and multiple layers. The fabrication of the FET back-SiO2 -gate configuration was made by depositing patterned source and drain Ti contacts on the dispersed MoS2 crystals to achieve the Ti/MoS2/SiO2/Si layer stacks. MoS2-based FETs with one and three layers were assembled and their electrical response analyzed by I–V output and transfer curves showing the typical characteristics of an n-type semiconductor channel operating in depletion mode. The electrical performance parameters of the devices, such as mobility and threshold voltage, were also determined from this analysis. Finally, to enhance their electrical response, the MoS2-based devices were thermally annealed at 200 °C for 30 min in Ar atmosphere. The increase in the mobility of the device was 176% compared to the device before the treatment.

Selection of output inverter for microgrid

The paper considers the problem of a microgrid output inverter selecting, when information about operating conditions is uncertain. The following factors are considered as sources of uncertainty in information about operating conditions: the possibility of the load increasing in the area, for which the microgrid is being designed, the prospects for its integration into the local power supply system, based on the microgrid, operating in the given region, as well as possible changes in the element base due to import substitution.
 A system of criteria and a methodology for optimal selection have been developed, based on a combination of multi-vector optimization approaches and the hierarchy analysis method. The quality criterion of generated energy, the criterion of reliable operation in conditions of information uncertainty and the criterion of economic indicators were cho- sen as vector criteria. The total number of scalar criteria that are components of the specified vector criteria is seven. At the first stage of selection, an algorithm is used for expert assessment of the importance of vector criteria and their scalar components, as well as values of these criteria for compared alternatives, using of the hierarchy analysis method. At the second stage of selection, considered inverters are ranked according to a global criterion, calculated based on results of the first stage. The technique is demon- strated by choosing between three well-known schemes of autonomous inverters: a voltage inverter with PWM-shaping of the output curve, a current inverter with a variable struc- ture and a group multilevel inverter based on a universal source of levels, when they are operating in autonomous or integrated into the system of other microgrid modes. The de- scribed selection technique can be used, when other microgrid conversion equipment de- vices are selecting.

Reliability of a method to assess corticomotor excitability of lower limb muscles using a normalized EMG motor thresholding procedure

Given the importance of determining intervention-induced neuroplastic changes with lower extremity functional tasks, a reliable transcranial magnetic stimulation (TMS) methodology for proximal lower extremity muscles is needed. A pre-set fixed voltage value is typically used as the criterion for identifying a motor evoked potential (MEP) during the motor thresholding procedure. However, the fixed voltage value becomes problematic when the procedure is applied to proximal lower extremity muscles where active contractions are required. We sought to establish the reliability of a method measuring corticomotor excitability of gluteus maximus and vastus lateralis using normalized electromyography (EMG) as the criterion for identifying MEPs during the motor thresholding procedure. The active motor threshold for each muscle was determined using the lowest stimulator intensity required to elicit 5 MEPs that exceeded 20% maximal voluntary isometric contraction from 10 stimulations. TMS data were obtained from 10 participants on 2 separate days and compared using random-effect intra-class correlation coefficients (ICCs). Slopes from two input–output curve fitting methods as well as the maximum MEP of gluteus maximus and vastus lateralis were found to exhibit good to excellent reliability (ICCs ranging from 0.75 to 0.99). The described TMS method using EMG-normalized criteria for motor thresholding produced reliable results utilizing a relatively low number of TMS pulses.

Fiscal Policy in Public Health Crisis (COVID-19): An Analysis Based on IS-LM Model in China

The Chinese economy was severely impacted during the Novel Coronavirus pandemic (COVID-19). This paper will investigate the impact of the epidemic on different fields of the economy, such as consumption and investment, and the role of positive fiscal policy in the recovery of the national economy from the perspective of the government. In addition, this paper will then use the IS-LM model as the analytical method to explore the effect of fiscal policy through the movement of the curve. According to the model, in the face of the epidemic, the Chinese government has boosted economic growth through a series of fiscal policies such as increasing government subsidies, reducing taxes, and issuing consumption vouchers. Moreover, as demonstrated in the literature by different scholars, under the current condition of China, the effect of fiscal policy will be much better than that of monetary policy, and therefore it is the most effective way to address short-term shocks.

Linking the Extended Autonomic System with the Homeostat Theory: New Perspectives about Dysautonomias.

Dysautonomias are conditions in which altered functions of one or more components of the autonomic nervous system (ANS) adversely affect health. This essay is about how elucidating mechanisms of dysautonomias may rationalize personalized treatments. Emphasized here are two relatively new ideas-the "extended" autonomic system (EAS) and the "homeostat" theory as applied to the pathophysiology and potential treatments of dysautonomias. The recently promulgated concept of the EAS updates Langley's ANS to include neuroendocrine, immune/inflammatory, and central components. The homeostat theory builds on Cannon's theory of homeostasis by proposing the existence of comparators (e.g., a thermostat, glucostat, carbistat, barostat) that receive information about regulated variables (e.g., core temperature, blood glucose, blood gases, delivery of blood to the brain). Homeostats sense discrepancies between the information and response algorithms. The presentation links the EAS with the homeostat theory to understand pathophysiological mechanisms of dysautonomias. Feed-forward anticipatory processes shift input-output curves and maintain plateau levels of regulated variables within different bounds of values-"allostasis". Sustained allostatic processes increase long-term wear-and-tear on effectors and organs-allostatic load. They decreaseing thresholds for destabilizing and potentially fatal positive feedback loops. The homeostat theory enables mathematical models that define stress, allostasis, and allostatic load. The present discussion applies the EAS and homeostat concepts to specific examples of pediatric, adolescent/adult, and geriatric dysautonomias-familial dysautonomia, chronic orthostatic intolerance, and Lewy body diseases. Computer modeling has the potential to take into account the complexity and dynamics of allostatic processes and may yield testable predictions about individualized treatments and outcomes.

Household heterogeneity and the price puzzle in a new Keynesian model

This paper provides a new insight into the price puzzle using a new Keynesian (NK) model with household heterogeneity. To do this, we adopt a tractable heterogeneous-agent NK (THANK) model that nests the two-agent NK (TANK) and representative-agent NK models. We first demonstrate that when the share of liquidity-constrained (LC) consumers is high, the degree of inflation stabilization in the Taylor rule crucially affects whether the price puzzle occurs in the TANK model. Second, we show that regardless of the share of LC consumers, the price puzzle disappears in the THANK model with a discounted dynamic IS (DIS) curve. In contrast, for a compounded DIS curve, a higher share of LC consumers generates the price puzzle. Finally, we find that even in the case of a compounded DIS curve, reinforced interest rate smoothing can prevent the price puzzle.

Uncertainty Prediction of Offshore Wind Power Based on Outlier Processing, Data Noise Reduction and the Deep Learning Method

Background: Accurate prediction of offshore wind power is the basis for promoting the safe and economic operation of offshore wind farms. Objective: This paper proposes an uncertainty prediction learning model based on outlier processing, synchronous wavelet denoising and attention mechanism optimization to achieve accurate prediction of offshore wind power. Method: Firstly, the isolated forest is adopted to filter the outliers of offshore wind power data and delete the error data caused by equipment or humans. Secondly, a syn-chrosqueezing wavelet neural network (SWT) is applied to denoise historical wind power data, improve data quality, and lay a foundation for accurate prediction. Next, the offshore wind power prediction method based on IP-SO-LSTM-Attention is constructed to realize offshore wind power prediction, in which the attention mechanism is applied to focus on the influence of important features on the output of offshore wind power, and the improved particle swarm optimization algorithm is adopted to find the best network structure of LSTM-Attention to optimize the prediction effect. After predicting the point prediction results based on the SWT-IPSO-LSTM-Attention model, this paper sets MAPE, RMSE, MAE and other indicators to evaluate the prediction effect. Results: The prediction error MAPE of the proposed model is 4.12%. It is 63.21% higher than the benchmark model (SWT-BP) and 56.35% higher than the benchmark model (SWT-LSTM). Conclusion: Based on the point prediction results, this paper uses KDE (Gaussian) prediction results to calculate the out-put curve under different confidence levels and provides decisionmaking reference information for accurate decision-making.

Deconstructing the Macroeconomics' IS-LM Model: Its Assumptions and Simplifications

Deconstructing the Macroeconomics' IS-LM Model: Its Assumptions and Simplifications

Mathematical analysis of a spatiotemporal dynamics of a delayed IS-LM model in economics

The purpose of this research is to suggest and analyze a spatiotemporal of an IS-LM model with two delays, interest rate, liquidity preference and general investment function. The first delay into the proposed model refers to the time delay between the decision of investment and his implementation. However, the second one represents the delay in investment production. The well posedness of the model is proved. The stability analysis and the existence of Hopf bifurcation are obtained. Furthermore, numerical examples that confirm the analytical results are shown.

ОЦЕНКА СОГЛАСОВАННОСТИ ДЕНЕЖНО-КРЕДИТНОЙ И БЮДЖЕТНОЙ ПОЛИТИКИ В РОССИИ

The objectives of monetary and budgetary policy are considered, the main macroeconomic indicators are considered, conclusions are drawn about the dynamics of inflation, GDP, and public debt. The theoretical justification of the need to harmonize monetary and budgetary policies is presented, the IS-LM model is considered as a tool for determining the macroeconomic equilibrium of indicators. The problems of coordination of the budgetary and monetary policy of the Russian Federation are identified. The relevance of the study is due to the need to coordinate monetary and budgetary policies.

Polarized Coulomb field scattering in LaAlO3/SrTiO3 heterojunction field-effect transistors

LaAlO3/SrTiO3 heterojunction field-effect transistors (HFETs) were fabricated. Using a combination of measured current–voltage (I–V) output curves and gate-source capacitance–voltage (C–V) characteristic curves for the fabricated LaAlO3/SrTiO3 HFETs, and considering scattering mechanisms for longitudinal optical phonon, interface rough, electron-electron (E-E), acoustic phonon, and polarized Coulomb field (PCF), the channel electron mobility of LaAlO3/SrTiO3 HFETs has been calculated and analyzed. The results showed that PCF scattering is a significant carrier scattering mechanism in LaAlO3/SrTiO3 HFETs. The heterostructure of the LaAlO3/SrTiO3 system has strong polarization characteristics. This paper is the first to demonstrate that PCF scattering is a significant carrier scattering mechanism in LaAlO3/SrTiO3 HFETs, following GaN HFETs, thus demonstrating that LaAlO3/SrTiO3 HFETs also have PCF scattering effect.

Analysis on flexibility resources of Western Inner Mongolia power grid

This paper defines the concept of flexibility in the power system as the ability of the individual components or the system itself to meet the net load changes and respond to power regulation demands. It then reviews the existing methods for evaluating flexibility and their classification, identifies the advantages and disadvantages of these methods, and provides a mathematical model for the flexible operation of the Western Inner Mongolia power grid. Based on the data provided by production units, the paper summarizes the output characteristics of various flexibility resources in the Western Inner Mongolia power grid, including the output curves of typical photovoltaic power stations, typical wind power plants, the overall load curve, typical regional load curves, and power transfer curves of three interconnecting busbars. It also studies the potential regulation capabilities of new energy sources, loads, and interconnecting lines. Finally, the paper evaluates the flexibility level of the Western Inner Mongolia power grid by drawing the net load curve, points out the shortcomings in flexibility in the construction of the new power system in the Western Inner Mongolia region, and provides corresponding suggestions.

Highly Robust Self‐Switching Mode Triboelectric Nanogenerator Based on Misaligned Triple‐Cam Design

To enhance the robustness and lifespan of triboelectric nanogenerator (TENG) and facilitate its industrial applications, herein, a self‐switching mode TENG that combines the advantages of contact mode and noncontact mode TENG is presented. Noncontact mode TENG prevents material wear but generates insufficient power, whereas contact enhances power generation by increasing the charge density on the electrode surface. The proposed device can automatically switch between contact and noncontact modes through a triple‐cam mechanism and gear train deceleration mechanism. Experimental results determine the optimal force value of 6 N and corresponding cam height of 1 mm, contact time of 8 min, and noncontact time of 30 min, to ensure good power output and minimal material wear. Simulation results demonstrate that the three cams have more stable mechanical properties and can improve the device's robustness. The cam repose angle and gear train structure are optimized based on the curves of electrical output versus time for both modes, and a method is proposed to extend the self‐switching time. The self‐switching mode TENG has a longer life than the other two modes, with its transfer charge maintaining 90% of its initial value after 80 h of continuous operation.

International Evidence on the Interest Rate Effect in Dynamic IS Curves

ABSTRACT A number of studies have found little evidence of the effect of the interest rate in dynamic IS curves. We show that this is due to de-trending. The interest rate has a weak effect on the output gap even when controlling for wealth effects. However, when the IS curve is formulated in an error-correction form, we find a significant interest rate effect. Furthermore, we find that the nominal interest rate explains output dynamics better. Lastly, there are significant effects of long-term interest rates in emerging markets, which may justify the use of yield curve control policies in these economies.

قياس العلاقة التوازنية بين متغيّرات IS-LM-BP ومؤشّرات الاستقرار الاقتصادي في نيجيريا

The concept of economic balance occupies great importance in most of the world's economies, as it is the axis around which the discussion of economic thought revolves in various economic schools. Economic thought is in a state of continuous development and works to provide a model through which the general balance in the overall economy can be determined despite the difficulty of finding common relationships between all... Markets and the possibility of describing them in an integrated applied model that allows determining the equilibrium at the same time. Therefore, this study came to clarify the possibility of determining the total equilibrium through the IS-LM model, which works on equilibrium by combining the commodity market IS on the one hand and the money market LM on the other hand. The BP model was also added, which works to achieve balance in the external sector. Therefore, in this study, we can achieve balance internally and externally through the IS-LM-BP model, as the study addressed the impact of this balance that can be achieved on some indicators of economic stability. By determining an equilibrium interest rate and income, which is the final result of a set of economic relations.

Losing traction? The real effects of monetary policy when interest rates are low

Based on a panel of 18 advanced countries starting in 1985, we find that monetary transmission to economic activity is substantially weaker when interest rates are low. The results hold when controlling for potential confounding non-linearities associated with debt levels and the business cycle as well as for the trend decline in equilibrium interest rates. These findings suggest that the observed flattening of the Phillips curve has gone hand in hand with a steepening of the IS curve as interest rates remained persistently low, making monetary policy trade-offs more challenging.

Study on a performance matching method of wind rotor and generator based on energy transfer.

Wind power systems are a promising form of energy supply. At present, most of the studies focuses on the performance of individual components such as wind rotors or generators, and the overall output effect of wind power system is determined by the characteristics of wind rotor and generator and their combined characteristics. However, the evaluation of the overall output characteristics of the system is rarely considered. In order to investigate the overall output of the system quickly, a performance matching method of wind rotor and generator based on energy transfer is proposed in this paper. Based on the series operating characteristics of the wind power system model, the energy transformation process of the wind rotor, generator and the whole system are unified described by energy transfer. On the premise that the performance of wind rotor and generator is known, the transfer function model of each component is established, and on this basis, the transfer function model of the overall system is obtained. Then, the overall output effect of the system is analyzed and evaluated by this system transfer function model. The performance of the model is analyzed and compared by using a vertical axis wind power system coupling test bench and MATLAB/Simulink software. The results show that the error between the system output based on the theoretical model and the wind tunnel test is less than 6.5%, and the trend of the simulation and the test curve of the system output is consistent. Therefore, this method can be used to quickly predict the overall output performance of the wind turbine and generator on the premise that the performance of each component is known, without the need to connect each component to a wind power system for testing.

The Impact of Government Intervention on Firms' Investment Decisions in China: An Extension in the IS-LM Model

This essay examines how government interventions affect the firms in China, where political connections are valued as one of the essential factors in this fast-growing economy. This research aims to show that the Chinese government treats SOEs and non-SOEs differently by offering different interest rates. This paper contributes to allowing the policymakers to notice the difference in the responsiveness of SOE and non-SOEs investment. The government can plan its expansionary policy schemes by setting the interest rates according to the relative sensitivities of firms to overcome economic fluctuations. The primary methodology is an extension of the IS-LM model, which studies how the exogenous change in policies affects the equilibrium level of income. According to the correlation analysis, SOE investment has an intense negative relationship with interest rates. Still, the non-SOE investment is less responsive than the SOE investment, although it also has an opposite trend with the interest rates. This study modifies the IS-LM curve based on Chinese government intervention behavior and contributes to the further exploration of the investment behavior of firms under policy changes. The Chinese economy is currently rebounding from the aftermath of the pandemic, as the government abandoned its Zero-COVID regime. Chinas policy-induced recovery will generate a considerable contribution to global growth according to the IMFs forecasts, released on January 30th, 2023. This research topic is necessary to be developed as it studies the reaction of firms when the government applied its policy tools to spur the economy.