Compensation Characteristics Research Articles

Characteristics of full compensation and its association with total astigmatism: A cross-sectional study.

To evaluate the characteristics of full compensation and its association with the prevalence of total astigmatism (TA), and to analyze the effects of TA on uncorrected distance visual acuity (UDVA). With random cluster sampling based on a school-based cross-sectional design, children aged 4 to 18 years were recruited in September 2020, Shandong Province, China. TA, anterior corneal astigmatism (ACA), and ocular residual astigmatism (ORA) were converted to vectorial components (J0, J45), followed by an assessment of the compensatory effect of ACA by ORA. Astigmatism was defined as a cylinder that was better than or equal to 0.75 diopters (D). Logistic regression analysis was used to assess the related factors for children with full compensation, and the generalized linear model was used to assess the influence of TA on UDVA. Out of 4,494 eligible children, data of 4,145 children (92.3%, 9.23 ± 3.15 years, 50.4% boys) were included in the statistical analysis. The prevalence of TA (27.9%) increased significantly with age (Ptrend < 0.001). The distribution of full compensation in J0 and J45 components were similar (22.1% and 25.6%, respectively), which decreased with age (Ptrend < 0.001). The closer the refractive status was to emmetropization, the higher the proportion of full compensation and the lower the prevalence of TA were. Shorter axial length (J0: Odds Ratio (OR) = 0.76, 95% confidence interval (CI): 0.61 to 0.94, P = 0.010), better UDVA (J0: OR = 0.37, 95% CI: 0.21 to 0.65, P < 0.001; J45: OR = 0.34, 95% CI: 0.20 to 0.59, P < 0.001), and longer average corneal curvature radius (J0: OR = 3.72, 95% CI: 2.18 to 6.34, P < 0.001; J45: OR = 2.82, 95% CI: 1.67 to 4.76, P < 0.001) were associated with full compensation. Higher TA was associated with a worse UDVA (β = 0.03, 95% CI: 0.02 to 0.04, P < 0.001). The prevalence of TA gradually increased with age, and showed a U-shaped distribution with increased refraction. Full compensation was associated with smaller TA and better UDVA. This indicated that considering the compensatory effect of ORA is vital for astigmatism correction in clinical work, which may improve the visual quality.

Dynamic Voltage Restorer Based on Integrated Energy Optimal Compensation

This paper presents an advanced dynamic voltage restorer with integrated energy optimal compensation (EOC-DVR), which combines the advantages of pre-sag compensation and energy minimization compensation. The performance parameters of the EOC-DVR, such as the compensatory capability, loss of energy, and duration of compensation, can be balanced by this optimal compensation strategy. Additionally, the impact on the load is further reduced by the proposed method. By analyzing the working process of optimal comprehensive energy, the compensation limit of the strategy is discussed. After that, both the voltage and active power of the system for compensating are obtained by analyzing the compensation characteristics of the strategy. Therefore, the relations of the formula and curve between the related physical quantities can be obtained. Finally, simulation results based on MATLAB/Simulink are provided to verify the effectiveness of proposed compensation method.

Ідентифікація стану оплати праці та можливості розвитку гідної оплати праці у промисловій галузі України

Ensuring the sustainable development of industrial enterprises depends, to a large extent, on motivating the personnel to achieve set goals, which is primarily shaped by a factor such as «labor payment». This article proposes an approach to identify the status of labor payment and assess its dynamics by types of economic activities in the industry of Ukraine from the perspective of ensuring fair labor compensation. The use of taxonomic analysis as an identification tool allowed us to: establish the types of economic activities in the Ukrainian industry with the best and worst labor payment status; identify key changes in the field of labor compensation (both by specific types of economic activities and overall in the industry); group types of economic activities in the industry by the level of development and the manifestation of fair labor compensation characteristics. Based on the summary of the analysis results, a deterioration in the state of labor payment has been identified across most types of economic activities in the industrial sector, allowing it to be classified as unsatisfactory. The main obstacles to ensuring a fair level of labor compensation have been identified: low wage levels (below the country's average, particularly in 2021); inefficient allocation of labor payment expenses; and the presence of wage arrears. Directions for reforming and improving the labor payment policy in Ukraine's industry have been determined, both at the state level and at the level of individual enterprises.

Nonlinear Transient Mathematical Model of Large-Capacity Synchronous Condenser Based on Time-Varying Reactance Parameters

Large-capacity synchronous condenser (SC) is an essential dynamic reactive power compensation device in an Ultra-high voltage direct current (UHVDC) transmission system. The particular transient operating state and structural characteristic of SC lead to a severe magnetic saturation effect during transient operation. To accurately describe the dynamic characteristics of SC, it is urgent to establish a transient mathematical model considering the magnetic saturation effect. Therefore, this paper proposes a nonlinear transient mathematical model for SC based on time-varying reactance parameters and gives a calculation method for time-varying reactance parameters. The mathematical model proposed in this paper is verified by taking a 300MVar SC as the research object. This condenser is connected to the power grid at the sending end of the UHVDC transmission system. The proposed mathematical model, the traditional fixed-parameter transient mathematical model, and the saturated standard SG model used in the power system were used to simulate the voltage generated by dynamic reactive power compensation characteristics of SC during a drop failure. Compared with the fault test results, the accuracy of the proposed mathematical model is verified. The effect of magnetic saturation on the dynamic reactive power compensation characteristics was analyzed, respectively. In addition, the accuracy of the proposed mathematical model is closer to the actual motor state, which is helpful for further research on the operation analysis and state monitoring of SC.

Modeling and simulation analysis of active heave compensation control system for electric-driven marine winch under excitation of irregular waves

The six-degree-of-freedom (6 DOF) motion of the mother-ship, which is caused by wave fluctuation, makes offshore operations difficult. To solve this problem, various heave compensation systems were proposed, as well as the law of wave motion. These heave compensation systems included passive heave compensation system, semi-active heave compensation system, and active heave compensation (AHC) system. However, the empirical formula of wave motion is not suitable for practical offshore operations, and rare AHC systems take the characteristic of compensation into consideration. To study the compensation characteristic of the AHC system based on electric-driven marine winch in the actual sea condition and improve the accuracy of compensation, this work uses the measured data of wave motion, and deduces the motion equations of multi-axial driving system. By substituting the above elements into the AHC system and designing the sliding mode controller (SMC), the simulation results show the ideal compensation effect of the system. By comparing with experimental results, it is concluded that the driving system operates in according with the specified states, and the compensation performance of system is effective. The overall work is conductive to the research on AHC system, as well as the exploitation of marine resources.

Rhizospheric compensation of nutrient cycling functions dominates crop productivity and nutrient use efficiency

The influence of fertilization on crop nutrient use efficiency (NUE) and productivity remain unclear. Here, to assess how fertilization management influences the soil microbial communities and their functional profiles and consequently affects NUE and crop productivity, we established a field experiment with mineral and combined organic-mineral fertilization as well as mineral fertilizer reduction practices. The composition of the microbial community was measured by high-throughput amplicon sequencing, and its functional profile was predicted using PICRUSt (Phylogenetic Investigation of Communities by Reconstruction of Unobserved States) software. Our results demonstrated that fertilization management significantly shifted the rhizosphere bacterial community and regulated the compensation intensity of nutrient cycling-related functions, which means the rhizosphere bacterial community assembles to harbour greater nutrient cycling-related functions in lower available nutrient conditions to meet the nutrient requirements of the host plant. Moderate compensation intensity of nutrient cycling functions contributed to the highest NUE and crop productivity being achieved in the combined organic-mineral fertilization treatment. However, insufficient fertilizer input induced intense functional compensation, while standard mineral fertilizer input resulted in weakened functional compensation of nutrient cycling functions, both of which decreased NUE and crop productivity. Overall, this study provides new insights into the key roles of the rhizosphere microbiome in improving NUE, and suggests that the functional compensation characteristics of the rhizosphere microbial community may be a sensitive indicator of nutrient supply and demand relationships as well as a predictor of NUE.

Application of MMC-RPC in High-Speed Railway Traction Power Supply System Based on Energy Storage

In order to effectively improve the power quality and utilize railway regenerative braking energy in high-speed railway traction power supply system, this paper adopts the Modular Multilevel Converter type Railway Power Conditioner (MMC-RPC) with distributed super-capacitor (SC) energy storage (ES) scheme. Firstly, the single-phase MMC mathematical model is established, and the power compensation characteristics of MMC-RPC are derived. Secondly, the Virtual Synchronous Generator (VSG) control strategy is adopted to provide inertial support. Compared with the double closed loop (DCL) control, it has better anti-disturbance and dynamic performance. Then, based on the VSG control, a two-stage circulating current suppression strategy is proposed, in which Quasi-Proportional Complex Integral (QPCI) control is used to suppress the bridge arm circulating current, and integrated Proportional Integral-Quasi Proportional Resonant (PI-QPR) control is an improvement of the VSG control to further suppress the circulating current inside the VSG. Furthermore, the virtual DC motor (VDCM) strategy was proposed to control the charge and discharge of the distributed SC connected to MMC-RPC to recycle railway braking energy. Finally, simulation results of the VSG small signal model and the MMC-RPC simulation model on the Matlab/Simulink platform verify the effectiveness, stability of VDCM and improved VSG controls in the MMC-RPC.

COMPENSATION OF HARMONICS TO IMPROVE POWER QUALITY USING HYBRID ACTIVE POWER FILTER

This paper presents design, simulation and development of hybrid active power filter for mitigation of the power quality problem at ac mains in ac-dc power supply feeding to a nonlinear load. The power filter is consisting of a shunt passive filter connected in series with an active power filter. At first passive filter has been designed to compensate harmonics. The drawback associated with the passive filter like fixed compensation characteristics and resonance problem is tried to solve by HAPF. Simulations for a typical distribution system with a hybrid power filter have been carried out to validate the presented analysis. Harmonic contents of the source current has been calculated and compared for the different cases to demonstrate the influence of harmonic extraction circuit on the harmonic compensation characteristic of the shunt hybrid power filter.

Sagittal Parameters of Spine-Pelvis-Hip Joints in Patients with Lumbar Spinal Stenosis.

To explore sagittal compensation characteristics, including extra spinal-pelvic parameters and distal hip parameters, for analysis in middle-aged to the older patients with lumbar spinal stenosis (LSS) without spinal deformity and clarify the fitting relationship between the main sagittal parameters. This retrospective single-center study included 205 patients with LSS in our department from January 2016 to December 2018, including 153 women (74.6%), with an average age of 67.6 ± 7.1 years. Sagittal parameters were obtained on the whole spinal lateral radiograph. Spinal parameters include thoracic kyphosis (TK), thoracolumbar kyphosis (TLK), and lumbar lordosis (LL). Pelvic parameters include pelvic incidence (PI), pelvic tilt (PT), and sacral slope (SS). Hip parameters include pelvic rotation (PR) and hip inclination angle (HIA). Spine-pelvic parameter is spino-sacral angle (SSA). Sagittal balance parameter is sagittal vertical axis (SVA). PI-LL, PT, SVA, HIA, and TLK were regarded as primary results, and the others were secondary outcomes. The independent sample t-test was used to compare gender. Pearson correlation analysis was used to evaluate the correlation between primary results and secondary results. We take PI-LL, PT, SVA, and TLK as dependent variables and include relevant factors for analysis. In the case of gender, PI, PI-LL, and PT were found smaller in men than women, but TK is greater in men than women (27.3° ± 6.1° vs 23.3° ± 7.7°, p=0.033). PI-LL was positively correlated with PT (r=0.608, p < 0.001) and negatively correlated with HIA (r=-0.193, p=0.010); PT was negatively correlated with HIA (r=-0.289, p < 0.01). As to the relationship between primary and secondary results, HIA was positively correlated with SS and PR (p < 0.01). SVA was positively correlated with SSA (r=0.341, p=0.010). The positive influencing factors and risk factors of SVA were SSA, and PI-LL played a negative regulatory role through proximal TK, the distal PT plays a positive regulatory role. The regulation of PI-LL was compensated through both TK and PT, with a fitting relationship of PI-LL=0.5 × PT - 0.2 × TK. There was a close interaction among spine-pelvic-hip sagittal parameters. We found the matching of PI-LL in the domestic middle-aged and elderly LSS population is regulated by thoracic spine and pelvis.

Design and Development of a Cold-Flow Test-Bench for Study of Advanced Nozzles in Subsonic Counter-Flows

As advanced nozzles may offer alternative solutions to conventional nozzles for the future class of reusable launch vehicles, a critical aspect is to tailor these novel technologies to current recovery strategies, more specifically to vertical landing sustained by retro-propulsion. Researchers at Technische Universität Dresden have developed a dedicated test-bench for the vacuum wind tunnel facility, where Advanced Nozzle Concepts (ANCs), such as aerospike and dual-bell nozzles, are tested in cold-gas configuration while invested by subsonic counter-flows. The main objective of the test campaign is to evaluate the performance and altitude–compensation characteristics of such ANCs by simulating a vertical landing manoeuvre through the variation of ambient pressure experienced during the landing burn. A detailed description of design and development of the test-bench, together with preliminary results from the commissioning activities, are here offered to the reader. The force measurements, together with pressure and temperature data, contribute to evaluate thrust levels and coefficients, as well as the monitoring of the interaction between the nozzle cold-flow and the opposing free-stream. A background-oriented schlieren system allows to visualise the external flow-field. In conclusion, an outline of the upcoming test campaign and a description of the expected results is offered.

Study on flow force compensation characteristics and optimization design of jet guiding groove

A jet guiding groove is designed on the spool to compensate the steady-state flow force. The steady-state flow force model is analyzed and derived. The influence of structural parameters on steady-state flow force is studied by CFD simulation. The response surface method is used to construct the steady-state flow force polynomial regression model. The optimal structure size of the jet guiding groove is obtained. The steady-state flow force compensation coefficient is defined and calculated. Results show that the compensation effect decreases with the increase of pressure difference. However, at the same pressure difference, the absolute value of the compensation coefficient of the spool with jet guiding groove is less than that of the spool without jet guiding groove. The results show that the jet guiding groove can effectively compensate the steady-state flow force and improve the control accuracy of the valve.

Improved Compressed Sensing Reconfiguration Algorithm with Shockwave Dynamic Compensation Features

This paper proposes a regularized generalized orthogonal matching pursuit algorithm with dynamic compensation characteristics based on the application context of compressive sensing in shock wave signal testing. We add dynamic compensation denoising as a regularization condition to the reconstruction algorithm. The resonant noise is identified and suppressed according to the signal a priori characteristics, and the denoised signal is reconstructed directly from the original signal downsampling measurements. The signal-to-noise ratio of the output signal is improved while reducing the amount of data transmitted by the signal. The proposed algorithm’s applicability and internal parameter robustness are experimentally analyzed in the paper. We compare the proposed algorithm with similar compression-aware reconstruction and dynamic compensation algorithms under the shock tube test and measured shock wave signals. The results from the reconstruction signal-to-noise ratio and the number of measurements required for reconstruction verify the algorithm’s effectiveness in this paper.

Compensation characteristics and hysteresis loops of an edge-decorated graphene-like Ising multilayer nanoparticle

The Monte Carlo simulation was applied to examine the compensation characteristics and hysteresis behaviors of an edge-decorated graphene-like Ising multilayer nanoparticle. The influence of various Hamiltonian parameters such as crystal field and exchange coupling on the magnetic properties is illustrated. Under certain Hamiltonian parameters, the system can exhibit interesting magnetic phenomena such as double compensation temperatures, multiple saturation magnetizations, double-peak susceptibility χ curves and triple-loop hysteresis behaviors, which probably can be applied to multiple magnetic recording.

Modeling and Extended State Observer-Based Backstepping Control of Underwater Electro Hydrostatic Actuator with Pressure Compensator and External Load

Electro hydrostatic actuator (EHA) has been successfully developed for flight control applications to replace the cumbersome centralized hydraulic system. It also has excellent potential for ocean applications due to its advantages on miniaturization and energy-savings. One of the special technologies for EHA’s underwater application is pressure compensation, which is used to equalize the return pressure of the hydraulic system and the seawater pressure. This paper investigates the modeling and control design of underwater EHA to improve performance, especially considering the effect of additional pressure compensator and uncertain external load. The nonlinear hydraulic model is extended by the dynamic characteristics of the pressure compensator. Two low-order extended state observers were constructed to cope with the external load fore and the effect of the pressure compensator, respectively. The backstepping methods were designed to guarantee the robust stability of the entire high-order nonlinear hydraulic system. Finally, the theoretical proving and simulation on Matlab/Simulink are conducted to demonstrate the high tracking performance of the proposed control strategy.

ONE-OFF COMPENSATION TO FAMILY MEMBERS FOR AN ACCIDENT AT WORK OR OCCUPATIONAL DISEASE

A one-off for family members in the event of the death of an insured person as a result of an accident at work or occupational disease shall be of an insurance nature. It is granted in the event of the death of an insured person who was covered by accident insurance. The benefit is paid by ZUS on the basis of a decision. It is paid from the accident fund, where the premiums paid for accident insurance are collected. In addition, the amount of the premium depends on the degree of risk of accident. The conditions for one-off compensation and its amount were structured in a schematic manner, since it was not necessary to determine the nature and size of the damage. Such rules for determining one-off compensation lead to simplification and scheme for compensation for damage. These features of compensation mean that the damage can be repaired in a limited manner. Accident compensation does little to meet the characteristics of civil law compensation. The extent to which the compensatory function of compensating for damage is to be carried out will depend on the type of damage and its extent, as well as on whether family members will be entitled to other accident benefits.

Study on the Influence of Triangular Groove Structure on Steady-State Flow Force Compensation Characteristics

In this study, a structurally improved spool was designed. The diameter of one side of the spool stem was reduced, making the spool stem into a rounded table shape. A triangular groove was circumscribed on the step and on the same side. After liquid flow was guided through the triangular groove, the flow direction changed. A flow component in the negative direction was generated, which reversely impacted the liquid flow in the positive direction. The liquid flow angle at the outlet increased; that is, jet angle increased and flow force decreased. The simulation results show that, increasing the depth, H, of the triangular groove has a positive effect on flow-force compensation and was conducive to the stability of the valve core. Properly increasing the groove’s bottom diameter, D1, of the triangular groove was conducive to the stability of the spool, but when D1 was too large, the flow force increased. The experimental results are consistent with the simulation results, which proves that the improved structure can effectively reduce the flow force of the spool.

Characteristics analysis of segmental and regional lumbar spontaneous compensation post thoracic fusion in Lenke 1 and 2 adolescent idiopathic scoliosis

ObjectiveTo explore the characteristics of compensation of unfused lumbar region post thoracic fusion in Lenke 1 and 2 adolescent idiopathic scoliosis.BackgroundPreserving lumbar mobility in the compensation is significant in controlling pain and maintaining its functions. The spontaneous correction of the distal unfused lumbar curve after STF has been widely reported, but previous study has not concentrated on the characteristics of compensation of unfused lumbar region post thoracic fusion.MethodA total of 51 Lenke 1 and2 AIS patients were included, whose lowest instrumented vertebrae was L1 from January 2013 to December 2019. For further analysis, demographic data and coronal radiographic films were collected before surgery, at immediate erect postoperatively and final follow-up. The wedge angles of each unfused distal lumbar segments were measured, and the variations in each disc segment were calculated at the immediate postoperative review and final follow-up. Meanwhile, the unfused lumbar curve was divided into upper and lower parts, and we calculated their curve angles and compensations.ResultsThe current study enrolled 41 females (80.4%) and 10 males (19.6%). Thirty-six patients were Lenke type 1, while 15 patients were Lenke type 2. The average main thoracic Cobb angle and thoracolumbar/lumbar Cobb angle were 44.1 ± 7.7°and 24.1 ± 9.3°, preoperatively. At the final follow-up, the disc wedge angle variation of L1/2, L2/3, L3/4, L4/5 and L5/S1 was 3.84 ± 5.96°, 3.09 ± 4.54°, 2.30 ± 4.53°, − 0.12 ± 3.89° and − 1.36 ± 2.80°, respectively. The compensation of upper and lower coronal lumbar curves at final follow-up were 9.22 ± 10.39° and − 1.49 ± 5.14°, respectively.ConclusionWhen choosing L1 as the lowest instrumented vertebrae, the distal unfused lumbar segments’ compensation showed a decreasing trend from the proximal end to the distal end. The adjacent L1/2 and L2/3 discs significantly contributed to this compensation.

Study on the streamflow compensation characteristics of reservoirs in Luanhe River Basin based on Copula function

Abstract With the rapid development of economy and society, the contradiction between supply and demand of water resources is increasing. Efficient utilization and allocation of limited water resources are one of the main means to solve the above contradictions. In this paper, the multidimensional joint distribution of natural streamflow series in reservoirs is constructed by introducing the mixed Copula function, and the probability of wet and dry encounters between natural streamflow is analyzed. Luan River is located in the northeastern part of Hebei Province, China, taking the group of Panjiakou Reservoir, Douhe Reservoir and Yuqiao Reservoir in the downstream of Luan River Basin as an example, the probabilities of synchronous and asynchronous abundance and depletion of inflow from the reservoirs are calculated. The results show that the probability of natural streamflow series between reservoirs is 61.14% for asynchronous wetness and dryness, which has certain mutual compensation ability. Therefore, it is necessary to minimize the risk of water supply security in Tianjin, Tangshan and other cities, and strengthen the optimal joint water supply scheduling of reservoirs. The research results are reasonable and reliable, which can provide reference for water supply operation of other basins.

Impairments and Compensations of Static Balance and Plantar Load Distribution in Patients With Chronic Stroke: An Observational Study

ObjectivesThe purpose of this study was to explore impairment and compensation characteristics of static balance and plantar load distribution in patients with chronic stroke. MethodsWe recruited 68 patients who had chronic stroke who could stand independently (stroke group) and 30 healthy individuals (control group) with the Zebris FDM platform. Static balance parameters, including center of pressure (COP) ellipse sway area, COP path length, and angle-θ between y and major axis, were compared between 2 groups under standard standing posture. In the stroke group, balance parameters were re-tested under their preferring standing posture. Plantar load distribution was also assessed. Another 8 patients with chronic stroke who could not stand independently and had to rely on a crutch were enrolled to analyze the characteristics of balance compensation. ResultsIn the stroke group, the ellipse sway area, COP path length, and angle-θ were significantly larger than those of the control group. Sixty-one (89.7%) patients preferred standing with the affected foot outward-forward supporting, and their preferring standing balance was better than that of standard standing. All patients who could not stand independently tended to compensate for balance with a crutch supporting laterally and also preferred standing with a typical posture- the affected foot was outward-forward. ConclusionsIn patients post stroke, static balance is impaired mainly at the lateral direction, and patients commonly locate the crutch laterally for compensation of lateral balance. Patients preferred standing with the affected foot outward-forward supporting, and their preferring standing balance was better than that of standard standing, which challenged the necessity of training standing symmetrically.

Review of enhanced power quality using unified power flow control system in electrical network

Flexible FACTS system of AC transmission. FACTS Devices can regulate electricity flow, develop the transmission capacity for power management. UPFC is a multipurpose fact controller carried on design of the constant voltage source. As an electrical device UPFC for rapid reactive power adjustment on high voltage electricity transport grid. Unified power flow control (UPFC). The latest FACTS gadget is UPFC. This combines series and shunting compensator characteristics and enables Power reactive and response to be controlled. UPFC utilization reduces difficulties in power quality including voltage sink and voltage surge. This article addresses UPFC and also several novel topologies for FACTS controllers.