Method For Improving Performance Research Articles

Seismic experiment and performance analysis on embedded optimized steel plate-reinforced concrete composite shear wall under multi-dimensional loading

In order to investigate the seismic performance of reinforced concrete shear walls under multi-dimensional loading mode and its effect on performance improvement, an embedded optimized steel plate-reinforced concrete composite shear wall is proposed. Based on the design principle that the shear wall could adequately bear multi-dimensional loading and the embedded steel plate could reach the full stress state, the X-shaped optimized steel plate (for in-plane loading mode) and the triangular optimized steel plate (for out-of-plane loading mode) are determined using different optimization methods. The combination scheme of these two plates is utilized in the oblique loading mode. Quasi-static loading tests are conducted on eight typical shear wall specimens, and performance parameters such as hysteresis curve, skeleton curve, ductility, stiffness degradation, strain evolution, and damage evaluation of the specimens are compared and analyzed. In addition, variable parameter analysis is performed using finite element software to compare the strain distribution state of each steel plate. The results indicate that the embedded optimized steel plate-reinforced concrete composite shear wall structure exhibits higher bearing capacity, greater deformation capacity, and superior energy dissipation capacity under different loading angles compared to the tradition reinforced concrete shear walls. This composite structure can provide greater lateral stiffness, and the optimized steel plate can reach the full stress state at all loading angles, effectively reducing the damage of steel bars and concrete. These findings offer a foundation for the study of seismic performance and performance improvement methods for shear wall structures under multi-dimensional earthquake action.

N × N MMI performance improvement method by suppressing propagation constant errors

We propose a method to improve the performance of N × N(N⩾3) multimode interference couplers (MMIs) by suppressing propagation constant errors through controlling excited guided modes and the width of MMI, without increasing their fabrication complexity. 5 × 5 MMIs were fabricated on a commercial 220-nm silicon-on-insulator (SOI) platform to verify the method. Measurement results show that insertion losses (ILs) and imbalances (Ims) are reduced from 2.28 dB to 0.16 dB and from 6.94 dB to 0.33 dB, respectively.

Energy harvesting from a fiber-constrained dielectric elastomer generator embedded into a novel floating wave energy harvester

Abstract With the increasing energy demand and growing concern about greenhouse gases emissions from fossil fuel combustion, converting the ocean wave energy into the electrical energy has emerged as a promising and sustainable solution. This paper proposes a novel floating ocean wave energy harvester based on the fiber-constrained dielectric elastomer generator (DEG) arrays and investigates the energy harvesting (EH) performance of the fiber-constrained DEG embedded into the harvester. A theoretical analysis model of the fiber-constrained DEG describing the free relaxation process is developed and verified by the existing experimental data. On this basis, the electrical energy and conversion efficiency of the fiber-constrained DEG are comprehensively analyzed under diverse system parameters, aiming to explore the feasible methods for performance improvement. Results show that both the electrical energy and conversion efficiency are enhanced by shortening the cycle period, boosting the output voltage, and increasing the time ratio of the rising segment in a cycle period. Variations of the electrical energy and conversion efficiency with the input voltage exhibit the non-monotonic behavior. In addition, at low input voltage, enlarging the maximum stretch ratio improves the EH performance, while at high input voltage, the overlarge maximum stretch ratio goes against the performance improvement. The average output power of the harvester with different lengths of rods in its displacement magnifying mechanism is also investigated. Results show increasing the rod length can improve the average output power. In addition, results can help to provide a guidance for designing a high-performance DE-based floating wave energy harvester.

A Performance Improvement Method of Omnidirectional Sound Source Tracking using a Square Microphone Array

A Performance Improvement Method of Omnidirectional Sound Source Tracking using a Square Microphone Array

Using Performance Improvement Methods to Evaluate Processes for Writing Multiple-Choice Test Questions in the Postlicensure Clinical Environment: A Case Study.

This article is the last of a four-part series to guide educators on the construction and evaluation of multiple-choice test items in the post-licensure environment. Previous articles in this series described the problem and the mechanics of test item construction and evaluation. A replicable strategy for evaluating the organizational process for constructing multiple-choice test questions is provided. Steps taken to create change are described; work tools are provided. Guidance and training are needed to create multiple-choice test questions. Many educators have not had training in item construction. Educators welcomed training. Personalized mentorship resulted in improvement. Asynchronous learning alone was helpful and well received and improved self-perceived knowledge, yet fell short of achieving competence. Voluntary training may not be adequate to assure enculturation of best practices without accountability standards and monitoring. Future research is indicated to assess the situation and provide national standards for adoption within health care organizations. [J Contin Educ Nurs. 202x;5x(x):xx-xx.].

Blade redesign based on inverse design method for energy performance improvement and hydro-induced vibration suppression of a multi-stage centrifugal pump

As the urgency of the global energy crisis escalates and environmental protection standards become more stringent, the industrial sector is placing increased emphasis on enhancing energy efficiency and advancing vibration control technologies. Within this context, multi-stage centrifugal pumps (MSCPs), pivotal in energy systems, play a crucial role in influencing both system performance and environmental impact. This paper embarked on employing an inverse design method (IDM) to innovate the redesign of MSCP blades, introducing a steady-state index for characterizing the intensity of unsteady pressure fluctuations, thereby streamlining optimization costs. Optimization techniques utilizing an artificial neural network model and a multi-objective evolutionary algorithm were employed to achieve an optimal balance between maximizing energy efficiency and reducing hydro-induced vibrations. The optimized MSCP enhanced not only boosting performance but also a 2.75 % increase in weighted efficiency, significantly widening the high-efficiency operation zone. The improvement in vibration characteristics was manifested by an average reduction of more than 25 % in the amplitude of the primary frequency of pressure pulsations within the double volute, with a maximum reduction reaching 50.9 %. Furthermore, the research delved into the analysis of the internal energy dissipation mechanisms of MSCPs, drawing upon the entropy production theory and the enstrophy concept. This analysis reveals that energy dissipation in the mainstream zones is predominantly affected by shear enstrophy, whereas, in the wall regions, it is primarily governed by fluid velocity. The comprehensive performance enhancement of the optimized model is significantly credited to the refinement of the blade profile.

A novel model for the pavement distress segmentation based on multi-level attention DeepLabV3+

The identification and recognition of pavement distress are vital for automatic pavement evaluation. The computation efficiency and accuracy are the two factors that determine the evaluation model. Our study utilizes the state-of-the-art image segmentation method of DeepLabV3+ with the attention mechanism. This study aims to conduct the pavement distress segmentation on the Crack500 and GAPs384 datasets. Critical results are comprehensively provided with a comparison of different backbones and architectures. In this study, an adaptive probabilistic sampling method is proposed and adopted to compare with the random crop and resized images. The test result of the adaptive prob-sampling method on DeepLabV3-attention architecture outperforms other model results on the Crack500 dataset. On the other way, the test result of the adaptive prob-sampling method on DeepLabV3 without attention architecture works better in the GAPs384 dataset. The different results relied on the diverse characteristics of datasets, since GAPs384 datasets have different asphalt surface types and a wide variety of distress classes rather than simple crack information which Crack500 included. In addition, some performance improvement methods, such as batch normalization of image input, revising dice loss, and hyperparameters search, have been implemented in this work. The results are solid and reliable for concluding the critical analysis of methods and datasets. This study demonstrates the considerable potential of deep learning in the application of intelligent pavement evaluation. To advance the practical application of artificial intelligence on distress segmentation, we will explore more domain adaptive methods in future studies.

Analysis of performance improvement methods for offshore wind turbine blades affected by leading edge erosion

Leading edge erosion (LEE) poses greater challenges to the blade design of offshore wind turbines. This paper analyzes the influence of LEE on blade aerodynamic performance and wind turbine load based on high-power offshore wind turbines through the GH-Bladed computing platform. The study found that LEE severely weakens the blade aerodynamic performance, resulting in a lag in the wind turbine reaching its rated power. LEE expands the range of blade surface flow separation, leading to an increase in blade stall risk and a decrease in wind turbine load stability. The promotion of blade aerodynamic performance will cause an increase in blade force, which will strengthen the load level of both the blade and the wind turbine. The optimization of twist angle is an effective method to avoid the loss of power generation of wind turbines under LEE interference, but it is inevitable to cause a decrease in the load stability of wind turbines. Therefore, when the load safety margin of wind turbines is sufficient, adjusting the twist angle is an efficient technique to improve the blade aerodynamic performance and promote the stability of power output, which provides a novel solution for blade design of high-power offshore wind turbines.

A real-time performance improvement method for composite time scale

Abstract The composite time scale (CTS) provides a stable, accurate, and reliable time scale for modern society. The improvement of CTS’s real-time performance will improve its stability, which strengths related applications’ performance. Aiming at this goal, a method achieved by determining the optimal calculation interval and accelerating adjustment stage is proposed in this paper. The determinants of the CTS’s calculation interval (characteristics of the clock ensemble, the measurement noise, the time and frequency synchronization system’s noise and the auxiliary output generator noise floor) are studied and the optimal calculation interval is obtained. We also investigate the effect of ensemble algorithm’s initial parameters on the CTS’s adjustment stage. A strategy to get the reasonable initial parameters of ensemble algorithm is designed. The results show that the adjustment stage can be finished rapidly or even can be shorten to zero with reasonable initial parameters. On this basis, we experimentally generate a distributed CTS with a calculation interval of 500 s and its stability outperforms those of the member clocks when the averaging time is longer than ∼1700 s. The experimental result proves that the CTS’s real-time performance is significantly improved.

Evaluation of Vulnerabilities for the Spread of Carbapenem Resistant Organisms at Five Hospitals in India

Background: The 2022 WHO global survey on infection prevention and control (IPC) exposes significant gaps in IPC in the WHO Southeast Asia region. A better understanding of IPC vulnerabilities will inform improvement initiatives. We describe an evaluation of IPC practices known to prevent and contain carbapenem-resistant organisms (CROs) at hospitals participating in the United States Centers for Disease Control Global Action in Healthcare Network –Antimicrobial Resistance in India. Prior hospital evaluations suggest resistance to carbapenems among gram-negative isolates is up to 45%. Methods: We conducted a mixed methods evaluation including cross-sectional surveys, semi-structured interviews, and site observations at five hospitals (one government, two private tertiary care, and two private teaching) located in three cities. The number of hospital beds ranged from 362 to 2,011. Hospital and IPC program characteristics, and CRO prevention and containment activities were examined virtually. Site observations focused on hand hygiene, environmental cleaning, personal protective equipment (PPE), CRO containment practices and use of water for patient care. Results: All sites had IPC programs with established policies and qualified IPC staff. The IPC nurse-to-bed ratio ranged from 1:73 to 1:432 (mean, 1:209). Due to the integral role of microbiology staff in IPC at these hospitals, the two departments had strong communication channels associated with CRO identification. Screening for CRO colonization, if done, targeted patients from outside hospitals. Three of the five hospitals routinely implemented contact precautions for patients with identified CROs, displayed isolation signage at the bedside, and provided adequate PPE at point-of-use; however, all sites reported barriers to effective isolation and/or cohorting patients with CROs. Timely communication of CROs to clinical staff varied and no sites effectively relayed CRO status upon patient discharge to another facility. IPC teams identified gaps in environmental cleaning procedures and practices related to medical devices and equipment. All sites used alternatives to tap water for clinical care and sink etiquette was evident. Each IPC team performed audits of patient isolation and hand hygiene practices. Despite the considerable proportion of IPC resources dedicated to daily education and feedback in clinical areas, the IPC teams reported that improvement was often difficult to achieve. Conclusion: Given the high burden of CROs and limited IPC resources, detailed knowledge of IPC opportunities for improvement will help hospitals target novel interventions for CRO prevention and containment. Further investigation of colonization rates and effective performance improvement methods in these settings is needed.Disclosure: Patricia Simner: Research Contracts: BD Diagnostics, OpGen Inc., Qiagen Sciences Inc, T2 Diagnostics, Accelerate Diagnostics; Research Collaborators:Ares Genetics, CosmosID, IDbyDNA, Illumina; Consulting: OpGen Inc., BD Diagnostics, Shionogi Inc., GeneCapture, Qiagen Sciences Inc, Entasis, Day Zero Diagnostics, Next Gen Diagnostics

Research on drilling performance and tool life improvement methods of titanium alloy ultra-high-speed drilling bits

Research on drilling performance and tool life improvement methods of titanium alloy ultra-high-speed drilling bits

Bionic-response surface combination optimization method for latent heat storage performance improvement

Improving the melting and solidification rate of phase change material is crucial for enhancing the charging or discharging power of a latent heat storage system. This research proposed a novel two-tube heat exchanger latent heat storage unit with longitudinal fins of horsetail stem based on the bionic structure of horsetail stem cross-section. Numerical modeling of transient melting of phase change material in horsetail stem fins by natural convection was established. The model’s accuracy was verified and compared with horsetail stem fins and conventional straight fins. Moreover, we optimized and designed the new fin structure based on the response surface method with minimum melting time as the objective function. The optimization results show that the optimized ponytail fins have a more uniform temperature distribution of the phase change material, significantly eliminating the influence of the heat transfer hysteresis zone, and reaching the steady state more quickly under the heat storage condition. Compared to straight fins, optimized horsetail stem fins reduced the heat storage area by only 3.80% and shortened the phase change material melting time by 44.30%. The solidification time was also reduced by 54.59%. This study provides a new idea for the structural design of phase change heat storage fins.

Investigation of membrane stress continuously adjustable fiber optic acoustic sensor based on inverse piezoelectric effect

In this paper, a fiber optic acoustic sensor with continuously adjustable membrane stress technology is proposed, in which the stress exerted on the membrane can be flexibly adjusted by employing the inverse piezoelectric effect of lead zirconate titanate (PZT) tubular pedestal. First, the response mechanism of stress on the membrane is investigated theoretically. Based on this principle, the effect of adjustable stress on the flat response region and sensitivity of a single mode-multimode-single mode (SMS) fiber optic acoustic sensor are studied experimentally. The experimental results reveal that the flat response region of the sensor extends from 250 Hz to 450 Hz following the continuous increase in the membrane stress by changing the positive direct current voltage applied on PZT from 0 V to 100 V; meanwhile, the sensitivity decreases gradually from 336.5 mV Pa−1 to 162.7 mV Pa−1. The results also verify that the average minimum detectable pressure of the sensor is maintained at 0.54 mPa Hz−1/2 with a fluctuation of 0.08 mPa Hz−1/2 during the tuning process of membrane stress, which provides a flexible method for performance and applicability improvement of membrane-based fiber optic acoustic sensors.

Examining Sustainable Construction Waste Management Methods for Potential Performance Improvement

Examining Sustainable Construction Waste Management Methods for Potential Performance Improvement

The Relationship between Leadership and Performance in Enhancing the Sustainability of Social Enterprises

As social enterprises are established for the purpose of solving local problems, the sustainability of social enterprises is also important for local development. In order to increase the sustainability of social enterprises, performance improvement is necessary, and research on finding leadership styles suitable for social enterprises continues to be an important method of performance improvement. However, despite considerable interest in social enterprises over the past few decades, no consistent conclusion has been reached about what leadership style is appropriate for social enterprises. The present study aimed to find a suitable leadership style for social enterprises within the major leadership styles recognized in commercial enterprises. This study investigated the impact of the three major leadership styles in commercial enterprises on satisfaction and performance in social enterprises. Based on prior research, transformational leadership, with its capacity to promote change and support the achievement of goals, was considered appropriate for social enterprises, and entrepreneurship was also considered as challenge is important for balancing economic and social purposes. Servant leadership also focused on the importance of providing support for employees on the basis that employees’ success is the success of social enterprises. In this study, in order to broadly understand the performance of different leadership styles, job satisfaction and leader satisfaction were considered at the individual level, and economic performance and social performance were considered at the firm level. To support the argument of this study, the researcher aimed to survey employees who perceive a leader as possessing leadership qualities in social enterprises. For this purpose, a survey on transaction leadership was conducted among employees who participated in a three-week training session related to social enterprises. And on the last day of training, three leadership and four outcome variables were surveyed. Analyzing data form 170 respondents in 52 social enterprises whose evaluation of their leader’s transactional leadership was higher than the average, the present study found that transformational leadership had a positive relationship with all four variables considered as leadership outcomes. And this study found evidence that entrepreneurship had a positive relationship with job and leader satisfactions, but the impact of entrepreneurship on economic and social performance was insignificant. However, servant leadership had a positive relationship with leader satisfaction and social performance, but the impact of servant leadership on job satisfaction and economic performance was insignificant. These results contribute to confirming that the emphasis on leadership styles in commercial enterprises can effectively operate in social enterprises as well, and that the effectiveness of leadership can vary depending on the desired outcomes.

Research on the Performance Improvement Method for Lithium-Ion Battery in High-Power Application Scenarios

With the development of technology, high-power lithium-ion batteries are increasingly moving towards high-speed discharge, long-term continuous output, instantaneous high-rate discharge, and miniaturization, and are being gradually developed towards the fields of electric tools, port machinery and robotics. Improving the power performance of batteries can be achieved from multiple dimensions, such as electrochemical systems and battery design. In order to improve the power performance of lithium-ion batteries, this paper proposes design methods from the perspective of electrochemical systems, which include increasing the high-rate discharge capacity and low impedance of the battery. This article also studies the preparation of high-power lithium-ion batteries. This article aims to improve the rate performance of batteries by studying high-performance cathode materials, excellent conductive networks, and high-performance electrolytes. This article successfully screened high-performance cathode materials by comparing the effects of different particle sizes of cathode materials on electrode conductivity and battery internal resistance. By comparing the effects of electrolyte additives under pulse cycling, high-quality electrolyte additive materials were selected. By comparing the effects of different types, contents, and ratios of conductive agents on electrode conductivity, battery internal resistance, high-quality conductive agents, and appropriate ratios were selected. Finally, a 10 Ah cylindrical high-power lithium-ion battery with a specific energy of 110 Wh/kg, pulse discharge specific power of 11.3 kW/kg, an AC internal resistance of ≤0.7 m Ω, a 10C full capacity discharge cycle of over 1700, a 30C full capacity discharge cycle of over 500, and a continuous discharge capacity of 10C–30C, and a pulse discharge capacity of over 100C was prepared.

Study of a vortex-induced vibration piezoelectric wind energy harvester based on the synergy of multi-degree-of-freedom technology and magnetic nonlinear technology

A novel multi-degree-of-freedom and magnetic piezoelectric wind energy harvester (MNPWEH) is proposed in this work to improve the working bandwidth and output power for the wind energy harvesting based on vortex-induced vibration. In the process of studying the presented collaborative strategy utilizing multi-degree-of-freedom and nonlinear force enhancement technologies, four response states of the harvester are observed and named as inter-well state, intra-well state, pulse state, and intermittent state. The key factors determining these four response states are firstly obtained through a series of numerical simulations and pre-experiments. Then, a thorough investigation into the influence of structural parameters on these four response states and the output performance of the system has been conducted. The findings from the experimental results indicate that greater tip mass of the outer beams results in higher output voltage generated by the same state, while the excitation magnet spacing can be adjusted for meeting different requirements in power and working bandwidth. In the optimal configurations, the fabricated prototype finally can obtain a maximum average power of 1.83 mW under the condition of v = 5 m/s and s1 = 15 mm, and maintain a wide working bandwidth of 2 m/s −6 m/s with an average output power above 0.66 mW when s1 = 25 mm, respectively. The main contribution of this study has been to confirm the effectiveness of the collaborative use of the multi-degree-of-freedom technology and magnetic nonlinear technology in piezoelectric wind energy collection based on vortex-induced vibration. It also provides a deeper new insight into the performance improvement method for vortex-induced vibration piezoelectric wind energy harvester.

Magnesium phosphate cement-based engineered cementitious composites with polyethylene fibers: Performance improvement and design method

This study aims to improve the performance of magnesium phosphate cement-based engineered cementitious composites (MPC-ECC) and establish a systematic design method. The MPC-ECC with ultra-high ductility was prepared with the polyethylene (PE) fibers. The effect of the magnesium oxide to potassium dihydrogen phosphate mass ratio (M/P), quartz sand particle size (Sd), water to solid mass ratio (W/S), sand to binder mass ratio (S/B), fly ash (FA) content and fiber volume fraction (Vf) on the micro-mechanical properties and macro-mechanical properties of MPC-ECC were explored. The macro-mechanical properties of MPC-ECC with different curing temperatures and curing ages were also tested. And the SEM test was carried out to analyze the morphology of the MPC-ECC. The results showed that the ultimate tensile strain of MPC-ECC with optimal proportion can reach 7.1%. Even curing at −10 °C for 7 days, the ultimate tensile strain can reach 5.6%, and the compressive strength can reach nearly 20 MPa. And the microstructure is characterized by a highly dense morphology. Additionally, with the increase of M/P, the compressive strength of MPC-ECC increases, but the ultimate tensile stress decreases. The MPC-ECC with the Sd of 150–180 mesh shows significant strain hardening performance, and its ultimate tensile strain can exceed 5%. The large W/S is helpful to improve strain hardening performance, especially when the S/B is 0.2. In addition, when the FA content is 30% or 40%, the strain hardening performance of MPC-ECC is significant. The quantitative association model between ultimate tensile strain and pseudo strain-hardening indices was established. According to the association model, the design method of MPC-ECC was established, based on which the MPC-ECC with desired ductility can be realized. Meanwhile, the PSHσ and PSHJ are recommended to reach 2.15 and 25.1, respectively, at the same time for the MPC-ECC with ultimate tensile strain of above 3%.

A sequential excitation and simplified ant colony optimization based global extreme seeking control method for performance improvement

To date, it is lacking of an effective global extreme seeking control (GESC) approach to improve transient responses. Motivated by this engineering problem, a novel and general method of global ESC is proposed theoretically and technically in three steps: the step of a simplified ant colony optimization (SACO) algorithm for the task of global extreme seeking, the step of a sequential excitation (SE) algorithm for the improvement of both transient and steady state responses, and the step of discrete to continuous control conversion to control the real world dynamical systems. Both numerical simulations and physical experiments have been conducted to verify the effectiveness of the proposed controller with SE-SACO on the overall performance improvement in terms of transient responses, steady state responses and global extreme seeking. In comparison with the cutting-edge methods such as IABC-SHTS, SSA, BA and GA-ACO, the settling time and oscillations due to the proposed method are reduced significantly when keeping the global extreme seeking ability. It alleviates the conflict of global extreme seeking and good transient responses of the dynamical systems, an unsolved issue in the literature.

Numerical study on smoke temperature and exhaust efficiency in electric cable tunnel

Cable tunnels are the lifeline of cities. Once a serious fire occurs on cables, the toxic smoke generated by cable combustion spreads and escapes, causing serious harm to the surrounding environment and personnel. The heat generated can also ignite nearby combustibles, causing casualties and property damage. Based on the above issues, using fluid dynamics methods, fire dynamic simulation was used to simulate cable tunnel fire scenarios under four variables: wind speed, fire source power, smoke outlet height, and smoke exhaust airflow. The temperature distribution law of the ceiling smoke layer inside the cable tunnel, smoke generation law, tunnel smoke exhaust efficiency, and other factors were clarified, revealing the impact mechanism of the above factors on tunnel fire smoke exhaust efficiency and smoke performance improvement methods. The research results indicate that the combination mode of exhaust air volume and ventilation air speed can effectively control tunnel fire smoke, providing a reference for the fire prevention design of cables in urban cable tunnels.