Efficient System Research Articles

A hybrid optimization for distributed generation and D-STATCOM placement in radial distribution network: a multi-faceted evaluation

The deregulation of the power system, upward growth in electrical energy demand and network expansion have resulted in an increasing integration of distributed generation (DG) and distribution static synchronous compensator (D-STATCOM) into radial distribution systems (RDS). Nonetheless, the optimal allocation of these devices is highly important to derive immense benefits. This investigation narrows down on optimizing DG and D-STATCOM placement in IEEE 33-bus RDS with a view to increase bus voltages, decrease power losses as well as maximize economic gains. The study undertakes a comprehensive analysis comparing the technical, economic and environmental performance of DG and D-STATCOM; thereby enabling power engineers to make informed choices concerning which device will be most advantageous when it comes to delivering power in RDS. A fuzzy enhanced firefly optimization (FEFO) approach is proposed for the optimization and a multifaceted evaluation in terms of technical, financial and environmental is presented for effective decision-making on distributed energy resource deployment. D-STATCOM and wind DG integrations led to notable reductions in power loss and pollutant emissions, highlighting their effectiveness in improving power quality and reducing reliance on fossil fuels. While wind DG incurred a higher installation cost ($3,100,749.2) compared to D-STATCOM ($90,566.6), it achieved greater yearly power loss cost savings ($69,198 versus $47,619). FEFO’s efficiency in optimization stands out, aiding engineers in making informed decisions for optimizing D-STATCOM and wind-DG integration in the IEEE-33 RDS, ultimately enhancing system performance and cost-effectiveness through proactive planning. The integration of D-STATCOM and wind DG led to a significant improvement in distribution system efficiency, with D-STATCOM reducing real power loss by 28.7% and reactive power loss by 27.8%, while wind DG achieved greater reductions of 41.8% in real power loss and 37.5% in reactive power loss, alongside reductions in pollutant emissions of 1.5% and 2.2%, respectively.

Online judicial auction, loan availability, and corporate investment in China

Online judicial auctions can significantly impact corporate investment by enhancing creditor protection and facilitating loan availability. Using a dynamic difference-in-differences strategy, we find that the reform significantly boosts corporate investment. Mechanism tests reveal that the reform boosts corporate investment by improving corporate loan availability and creditors' willingness to lend. The effect is more pronounced in regions with high judicial auction turnover, high public participation, poorer legal environments, and lower banking competition, suggesting that these reforms enhance legal system efficiency and market competition. Additionally, we find that judicial auction reform reduces firms’ precautionary savings and fosters regional economic development. Overall, our study contributes to understanding the important role of creditor protection in corporate investment and provides insights for implementing digital judicial reforms.

Optimizing battery deployment: aging trajectory prediction enabling homogenous performance grouping

As battery deployments in electric vehicles and energy storage systems grow, ensuring homogeneous performance across units is crucial. We propose a multi-derivative imaging fusion (MDIF) model, employing advanced imaging and machine learning to predict battery aging trajectories from minimal initial data, thus facilitating effective performance grouping before deployment. Utilizing a derivative strategy and Gramian Angular Difference Field for dimensional enhancement, the MDIF model uncovers subtle predictive features from discharge curve data after only ten cycles. The architecture includes a parallel convolutional neural network with lateral connections to enhance feature integration and extraction. Tested on a self-developed dataset, the model achieves an average root-mean-square error of 0.047 Ah and an average mean absolute percentage error of 1.60%, demonstrating high precision and reliability. Its robustness is further validated through transfer learning on two publicly available datasets, adapting with minimal retraining. This approach significantly reduces the testing cycles required, lowering both time and costs associated with battery testing. By enabling precise battery behavior predictions with limited data, the MDIF model optimizes battery utilization and deployment strategies, enhancing system efficiency and sustainability.

Systematic screening and evaluation for an optimal adsorbent in a facade-integrated adsorption-based solar cooling system for high-rise buildings

Solar-powered adsorption chillers are a climate-friendly solution for building cooling, but costs and space requirements limit their widespread adoption. Recently developed adsorption cooling facade systems (ACFS) save installation space and further reduce CO2 emissions. The performance of ACFS depends on the implemented adsorbent. To achieve low costs and high performance of ACFS, this study systematically screened and scored adsorbents using the analytic hierarchy process (AHP) method, focusing on price, stability, driving temperature and adsorption capacity. This method narrowed down 293 adsorbents to top 10 scored adsorbents including 4 silica gels, 4 active carbons and 2 molecular sieves. The adsorbent-specific performance is evaluated by numerical simulation, revealing silica gel Type A++, Type 2560, Siogel and molecular sieve AQSOA-FAM-Z02 have peak adsorber temperatures 1.5 to 9.3 °C lower and increase solar cooling efficiency (SCE) by 25 % to 27 % compared to reference adsorbent Zeolite 13X. A sensitivity analysis of the Dubinin-Astakhov equation shows increasing E and decreasing V leads to an only minor adsorber temperature decrease and minor system efficiency increase. Lower temperatures and higher capacity cannot guarantee better system performance. This underscores that improving system performance cannot be achieved solely through adsorbent optimization but requires system optimization in parallel.

How hospital autonomy affects provider payment reform effectiveness.

Provider payment reforms (PPRs) have demonstrated mixed results for improving health system efficiency. Since PPRs require health care organisations to interpret and implement policies, the organizational characteristics of hospitals may affect the effectiveness of PPRs. Hospitals with more autonomy have the flexibility to respond to PPRs more efficiently, but they may not if the autonomy previously facilitated behaviours that counter the PPR's objective. This study examines whether hospitals with higher autonomy responds to PPRs more effectively. We used data from a matched-pair, cluster randomized controlled PPR intervention in a resource-limited Chinese province between 2014 and 2018. The intervention reformed the reimbursement method from the publicly administered New Cooperative Medical Scheme (NCMS) from fee-for-service to global budget. We interacted measures of hospital autonomy over surplus, hiring, and procurement (drugs, consumables, equipment, and overall index) with the difference-in-difference estimator to examine how autonomy moderated the intervention's effect. Autonomy over surplus (p<0.01) and procurement of equipment (p<0.01) were associated with relatively faster NCMS expenditure growth, demonstrating worse PPR response. They were also associated with higher expenditure shifting to out-of-pocket expenditures (p>0.05). Post hoc analysis suggests that hospitals with surplus autonomy had higher OOP per admission (p<0.01), suggesting profiteering tendencies. Other dimensions of autonomy demonstrated imprecise association. Hospitals with more autonomy may not necessarily respond more effectively to PPRs that incentivise efficiency when they had previously been encouraged to maximise profit. Policymakers should assess the extent of perverse incentives before granting autonomy and adjust the incentives accordingly.

The efficiency of financial management systems in selected schools in the Amathole West education district in the Eastern Cape, South Africa

Managing school finances by school governing bodies (SGBs) in South African secondary schools has proven to be a challenge that has several negative consequences for education, infrastructure, and other resources. The purpose of this article was to assess the efficiency of financial management systems (FMSs) in selected schools in the Amathole West education district. A case study design and qualitative approach were employed in the study. Purposive sampling was used to select SGB members from 2 schools in the district. The research participants were interviewed using face to face and telephonic interviews. We found that while there is understanding and alignment of financial systems by SGBs, insufficient or limited financial resources, inconsistencies in dealing with financial management matters, and government deposit allocation delays, SGBs’ level of education and bank operations pose challenges and lead to the misalignment of school operations. Based on the study, we suggest that SGBs adopt strategies to enhance the financial management of schools, namely monitoring and evaluation, the appointment of qualified SGB members, increased training, a stipend system for SGBs and timeous deposit of funds to schools.

Optimizing High-Speed Serial Links for Multicore Processors and Network Interfaces

In modern computing environments, high-speed serial links have become a critical component for ensuring efficient data transfer between multicore processors and network interfaces. These links, characterized by their ability to transmit data at very high rates over single or multiple lanes, are essential for meeting the increasing bandwidth demands of contemporary applications. The optimization of these serial links is crucial for maintaining performance, reliability, and energy efficiency in systems that leverage multicore processors and advanced network interfaces. This paper explores the key strategies for optimizing high-speed serial links in the context of multicore processors and network interfaces. We begin by examining the architectural considerations and design principles that influence the performance of serial links, including signal integrity, power consumption, and thermal management. We also discuss the impact of link speed and data encoding techniques on overall system efficiency. One of the central challenges in optimizing high-speed serial links is managing signal integrity across different operating conditions. Techniques such as equalization and adaptive filtering are essential for mitigating the effects of signal degradation due to channel impairments and crosstalk. The paper provides a detailed analysis of these techniques, including their implementation in both hardware and software.

Optimizing High-Speed Serial Links for Multicore Processors and Network Interfaces

In modern computing environments, high-speed serial links have become a critical component for ensuring efficient data transfer between multicore processors and network interfaces. These links, characterized by their ability to transmit data at very high rates over single or multiple lanes, are essential for meeting the increasing bandwidth demands of contemporary applications. The optimization of these serial links is crucial for maintaining performance, reliability, and energy efficiency in systems that leverage multicore processors and advanced network interfaces. This paper explores the key strategies for optimizing high-speed serial links in the context of multicore processors and network interfaces. We begin by examining the architectural considerations and design principles that influence the performance of serial links, including signal integrity, power consumption, and thermal management. We also discuss the impact of link speed and data encoding techniques on overall system efficiency.

Investigation on the radiative characteristics of ZnO-SiO2 nanofluids in spectral splitting photovoltaic/thermal systems

The application of nanofluid spectral splitting technology in photovoltaic/thermal (PV/T) systems has attracted more attention. In this study, zinc oxide and silica nanoparticles were selected to prepare ZnO-SiO2-H2O mixed nanofluids with different concentrations to investigate the radiative characteristics and their effect on PV/T system. An experimental system was established to measure nanofluids transmission properties in 0.36–2.5 μm, and the radiation characteristics were further analyzed using Mie scattering theoretical model. Besides, thermodynamic model was established to investigate the influence of mixed nanofluids on PV/T system performance. Results indicate that Mie theory can predict the radiative properties of mixed nanofluids well. The ZnO-SiO2-H2O nanofluids have better filtering performance than that of ZnO-H2O nanofluids under same particle concentration. When the mass ratio of ZnO/SiO2 is 0.01 %/0.05 %, the filtering efficiency of the nanofluid achieves 46.18 %. Increasing the concentration of SiO2 can regulate the transmittance of the ZnO-SiO2-H2O nanofluids and improve the PV/T system efficiency by 5 %. Based on ZnO nanofluids, the addition of SiO2 further optimizes PV/T system performance, increasing the system merit function (MF) value The nanofluid spectral splitting PV/T system for Si cells with a ZnO/SiO2 mass ratio of 0.003 %/0.056 % can reach a MF value of 1.342.

A Review of Factors Affecting the Efficiency and Output of PV Systems Applied in the Tropical Climate of South-South Nigeria

The increasing adoption of renewable energy for electricity generation has led to a growing application of photovoltaic (PV) systems in residential and commercial settings across Nigeria. This study aims to provide a comprehensive review of the factors affecting the efficiency and output of PV systems applied in the tropical climate of South-South Nigeria. The environmental benefits of PV systems further enhance their appeal as a direct method of converting solar energy into electricity. For remote communities in South-South Nigeria, often disconnected from the national grid, PV systems offer a viable alternative electricity source. However, the efficiency and output of PV systems are significantly influenced by various environmental conditions prevalent in the tropical climate of South-South Nigeria. The methodology employed in this study includes an extensive literature review and analysis of PV system installations in the region. Data was collected from various sources, including journal articles, conference proceedings, and reports, to identify the key factors impacting PV system performance in South-South Nigeria. The findings highlight that high temperatures, humidity levels, frequent dust accumulation, and potential sea salt effects due to coastal proximity are among the critical environmental factors affecting PV system efficiency in this tropical zone. The study concludes that while the region's climate provides advantages for solar energy harvesting, it also presents unique challenges that need to be addressed when implementing PV systems in South-South Nigeria. The authors recommend strategies to mitigate the environmental challenges faced by PV systems in this tropical climate, contributing to the optimization of solar energy utilization in the region.

Повышение энергетической эффективности работы тепловых сетей за счет утилизации тепловых потерь

The efficiency of thermal energy transfer, which is inevitably accompanied by heat losses through the insulation of pipelines, directly characterizes heating networks and centralized heat supply systems in general. The most important task in terms of current approaches to energy efficiency is to improve the efficiency of thermal energy transfer in modern heat supply systems. Currently known technical solutions to reduce heat losses through insulation of pipelines reduce heat losses, but not significantly. So, the purpose of this study is to develop a technical solution to reduce (even eliminate) standardized linear heat losses in heat supply networks of industrial enterprises. The authors have used methods of experimental research of heat transfer processes and mathematical modeling of heat and power equipment. A device for recycling heat losses is proposed. It is designed to reduce (even eliminate) normalized linear heat losses in heat supply networks of industrial enterprises. The permissible heat absorption of the device collector is determined, and a method for its regulation is described. An engineering method for calculation of the proposed device has been developed. The effectiveness of application of heat-reflecting screens in heating networks has been determined. A number of problems have been solved to improve the efficiency of heat supply systems of industrial enterprises using a device for recycling heat losses in the heating system channel.

Approximate analytical algorithm for pull-out resistance-displacement relationship of combined anchor system

Building upon an evaluation of the distinct advantages and limitations of anchor rods and anchorage plates, this paper introduces an integrated anchor-tensioning system that combines these elements in series. This innovative approach significantly enhances the pullout bearing capacity of the overall anchorage system. Based on the hyperbolic model of the distribution of lateral friction resistance of the anchor solid and the Winkler′s foundation model of load transfer of the anchorage plate, the theoretical analysis method for the analysis of the pullout bearing capacity and deformation of the combined anchorage system was established, and an approximate analytical equation for the relationship between pullout force and displacement was obtained. The results from indoor model tests, numerical simulations, and theoretical analyses were compared, verifying the reliability of the theoretical methods employed. The findings of this study significantly advance the discourse on the innovation of structural support configurations, thereby enhancing the operational efficiency of anchor-pull support systems.

Decision Matrix in an Autonomous Power System for Agro-Industrial Complexes with Renewable Energy Sources

The article focuses on systems analysis in identifying optimal areas for using distributed energy sources in the agro-industrial complex. Applying a systems approach enables a comprehensive assessment of various aspects of solar energy, wind energy, hydropower systems and integrated power plants that provide autonomous energy supplies. The research methodology includes a functional–structural approach that helps to assess the internal characteristics of systems, allowing for a deeper understanding of their structure and functions. This, in turn, leads to the creation of different models reflecting specific elements and relationships in energy systems. The main point is to take into account the level of functional and structural perfection, which helps to more accurately determine the areas where the introduction of renewable energy sources will be most effective, taking into account the specifics and needs of the agro-industrial complex. This approach not only contributes to a more optimal allocation of resources but also improves the sustainability and efficiency of energy systems in the face of a changing climate and the growing demand for environmental technologies.

Warehouse layout optimization for fishbone robotic mobile fulfillment systems

The rapid development of electronic commerce has increased demands for order fulfillment efficiency, making this a crucial challenge for warehouse systems. The study proposes a novel fishbone robotic mobile fulfillment system (FRMFS) to optimize warehouse layout and enhance the picking efficiency of automated warehouse systems, such as robotic mobile fulfillment systems (RMFS). Through the construction and analysis of mathematical models, the research demonstrates that FRMFS can significantly reduce the travel distance of robots when compared to traditional RMFS. This leads to an improvement in the overall picking efficiency of the warehouse system. The study also examines the impact of warehouse parameters, cross-aisle angles, and the number of picking stations on system operational efficiency. Simulation experiments confirm that FRMFS can reduce picking distances by 18%–28% compared to traditional RMFS. This makes it particularly suitable for complex warehouse systems with high requirements for operational response time and system throughput. Furthermore, the study introduces a point-based layout design method for picking stations in FRMFS, demonstrating its efficiency as a heuristic approach. This research presents a scientific analysis framework and model support for the operational design and optimization of FRMFS, offering valuable insights for management practices.

Hybrid Prisms: Transforming Medical Imaging Technology

This research article delves into the groundbreaking use of hybrid prisms in X-ray imaging devices, emphasizing their role in enhancing the precision and efficiency of imaging systems. A hybrid prism, which integrates the functions of a lens and a reflective prism, is a versatile optical component capable of manipulating electromagnetic waves across a spectrum of wavelengths, including visible light and X-rays. This technology significantly improves the focusing and imaging capabilities of X-ray devices, making it indispensable in fields such as medical diagnostics.

Optimization and exergoeconomic analyses of water-energy-carbon nexus in steel production: Integrating solar-biogas energy, wastewater treatment, and carbon capture

The steel industry is one of the hard-to-abate sectors for decarbonization, and direct electrification is not possible or economically infeasible. This study investigates the application of the Water-Energy-Carbon nexus in the steel industry through a multi-generation plant, addressing the industry's demands for water, energy, and alternative fuel. The proposed multi-generation plant consists of parabolic trough solar collectors, an organic Rankine cycle, urban wastewater treatment, carbon capture, anaerobic digestion combined with heat and power, a proton exchange membrane electrolyzer, and a steelmaking plant. Thermodynamic and exergoeconomic analyses are conducted to investigate the system's efficiency and economic performance. A sensitivity analysis is conducted to identify the optimal links between nexus resources, followed by a multi-dimensional evaluation and multi-objective optimization. The results showed that under base conditions, the plant can annually produce 900 ktons of steel, 105 GWh of net power, 430.1 tons of water, and 517 tons of hydrogen, while preventing 34.7 ktons of CO2 emissions. The exergy efficiency and unit exergy cost of the products are 46.1% and 57.8 $/GJ, respectively. Under optimized conditions, the plant achieves a maximum net annual power output of 160 GWh, an exergy efficiency of 46.9%, and a minimum unit exergy cost of 51.4 $/GJ.

Highly crosslinked polymeric matrix for efficient ultralong dual-mode afterglow with multiple responses

Organic persistent luminescence (OPL) materials have enjoyed a long term research interest for promising applications in optical encryption, bio-imaging and optoelectronic devices. However, to achieve further promotion in afterglow efficiency and stability for responsive OPL systems are still challenging. Herein, an efficient responsive OPL system is prepared by doping an acridine derivative in a highly crosslinked poly(N-methylol acrylamide) matrix. The resulted doped polymeric system exhibits persistent phosphorescence and thermally activated delayed fluorescence with a high afterglow quantum yield up to 82.8% under ambient conditions without photoactivation for oxygen consuming. Benefitted from the dense structure brought by the chemical crosslinking with rich hydrogen bonding, the system exhibits good resistance to different organic solvents and shows response to water without complete afterglow quenching. Moreover, the dual-mode delayed emission consisting of persistent delayed fluorescence and phosphorescence provides time- and temperature-dependent OPL color. Benefitted from the stable feature, high afterglow efficiency and multiple stimuli-responses, the system can serve as OPL inkjet printing, providing potential applications in anti-counterfeiting and data-storage.

Grouping research proposals with funding agency requirements: A contextualized language model and constrained K-means clustering approach

As the volume of research proposals increases and the interdisciplinary nature of research fields exacerbates the complexity of manual proposal grouping, the grouping of research proposals becomes increasingly vital in funding agencies’ evaluation procedures. Although previous ontology- and word embedding-based approaches have made valuable contributions to the advancement of research proposal grouping, their practical utility has been limited due to a lack of consideration of funding agencies’ requirements. This study proposes a systematic approach for grouping research proposals that aligns with three common requirements: size, cannot-link, and must-link constraints. The proposed approach utilizes KLUE-RoBERTa for proposal vectorization and constrained K-means clustering for proposal grouping with size constraints. We introduce a proposal pre-partitioning and a proposal vector centralization to simultaneously consider the cannot- and must-link constraints in grouping proposals. An empirical analysis of 3,665 proposals submitted to the National Research Foundation of Korea demonstrates the effectiveness and practicality of the proposed approach. Additionally, we conduct a comparative analysis of various combinations of methodological components to optimize this approach. The proposed approach is considered a valuable complementary tool for grouping proposals, enhancing the overall efficiency and effectiveness of the proposal evaluation system.

Phytohormones enhanced carbon fixation and biomass production in CO2 absorption-microalgae conversion system under light stress

CO2 absorption-microalgae conversion (CAMC) system can be a sustainable technology to achieve low-energy carbon capture and resource utilization in response to zero carbon. However, light stress could restrict the carbon utilization efficiency of CAMC system. In this study, melatonin (MT) and indole-propionic acid (IPA) as phytohormones, were used to promote the carbon fixation capacity and biomass yield of CAMC system under light stress, and the potential mechanism was also discussed. Both MT and IPA promoted the growth of Spirulina, and 10 mg-MT group obtained the highest biomass and carbon fixation capacity, which were 27.61 % and 30.62 % higher than control. MT and IPA promoted the activity of superoxide dismutase (SOD), catalase (CAT), and glutathione reductase (GR), enhancing antioxidant activity to avoid oxidative damage. The results of transmission electron microscopy (TEM) and cell apoptosis showed MT and IPA reduced cell membrane damage and apoptosis. Phytohormones induced the carbon flux flow to the synthesis of carbohydrate and protein, and increased carbohydrate and protein productivity. Moreover, the maximum phycocyanin content and yield were 13.74 % and 43.25 % higher than the control. Therefore, adding phytohormones was an effective strategy to achieve high-value bioresources of microalgae in CAMC system under light stress.

Modeling and SOC estimation of on-board energy storage device for trains under emergency traction

The sudden interruption of train power supply in an extreme environment will seriously threaten the safety of passengers and affect the operational efficiency of the railway system. In this case, the focus of attention becomes a method of running the train to the nearest rescue point based on the limited capacity of the on-board emergency energy storage device. Therefore, this paper reports research on the state of charge (SOC) estimation of train energy storage equipment to optimize the emergency traction strategy and energy utilization rate of trains to the maximum extent. First, with the emergency power supply of on-board lithium titanate batteries, the energy flow model of train emergency power supply is constructed for the first time. Second, based on the second-order equivalent circuit model and considering the utilization of regenerative braking energy, the relationship between battery capacity and open circuit voltage (OCV), temperature, current and SOC are constructed through experimental data, which significantly improves the accuracy and robustness of SOC estimation in complex and variable environments. Then, to effectively eliminate the impact of environmental on the estimation especially in the case of extremely low temperature (−20 °C), online model parameter discrimination and SOC estimation of lithium batteries are realized by combining recursive least squares with an optimal forgetting factor (FRLS) algorithm and a new temperature forgetting factor based adaptive extended Kalman filter (TFFAEKF) algorithm. The experimental results show that the proposed method achieves accurate SOC estimation, and the maximum error is less than 1% at different temperatures.