Unit Time Research Articles

Early-Neonatal, Late-Neonatal, Postneonatal, and Child Mortality Rates Across India, 1993-2021

The global success of the child survival agenda depends on how rapidly mortality at early ages after birth declines in India, and changes need to be monitored to evaluate the status. To understand the disaggregated patterns of decrease in early-life mortality across states and union territories (UTs) of India. Repeated cross-sectional data from the 5 rounds of the National Family Health Survey conducted in 1992-1993, 1998-1999, 2005-2006, 2015-2016, and 2019-2021 were used in a representative population-based study. The study was based on data of children born in the past 5 years with complete information on date of birth and age at death. The analysis was conducted in February 2024. Time and geographic units. Mortality rates were computed for 4 early-life periods: early-neonatal (first 7 days), late-neonatal (8-28 days), postneonatal (29 days to 11 months), and child (12-59 months). For early and late neonatal periods, the rates are expressed as deaths per 1000 live births, for postneonatal, as deaths per 1000 children aged at least 29 days and for child, deaths per 1000 children aged at least 1 year. These are collectively mentioned as deaths per 1000 for all mortalities. The relative burden of each of the age-specific mortalities to total mortality in children younger than 5 years was also computed. The final analytical sample included 33 667 (1993), 29 549 (1999), 23 020 (2006), 82 294 (2016), and 64 242 (2021) children who died before their fifth birthday in the past 5 years of each survey. Mortality rates were lowest for the late-neonatal and child periods; early-neonatal was the highest in 2021. Child mortality experienced the most substantial decrease between 1993 and 2021, from 33.5 to 6.9 deaths per 1000, accompanied by a substantial reduction in interstate inequalities. While early-neonatal (from 33.5 to 20.3 deaths per 1000), late-neonatal (from 14.1 to 4.1 deaths per 1000), and postneonatal (from 31.0 to 10.8 deaths per 1000) mortality also decreased, interstate inequalities remained notable. The mortality burden shifted over time and is now concentrated during the early-neonatal (48.3% of total deaths in children younger than 5 years) and postneonatal (25.6%) periods. A stagnation or worsening for certain states and UTs was observed from 2016 to 2021 for early-neonatal, late-neonatal, and postneonatal mortality. If this pattern continues, these states and UTs will not meet the United Nations Sustainable Development Goal targets related to child survival. In this repeated cross-sectional study of 5 time periods, the decrease in mortality during early-neonatal and postneonatal phases of mortality was relatively slower, with notable variations across states and UTs. The findings suggest that policies pertaining to early-neonatal and postneonatal mortalities need to be prioritized and targeting of policies and interventions needs to be context-specific.

Image fusion algorithm for the collaborative use of unmanned aerial vehicles

Currently, the applicable scope of unmanned aircraft application is increasingly expanding. The promising field of unmanned aircraft enhancement is the implementation of some collaborative actions during controlled flight. This paper considers some issues of the group application of unmanned aerial vehicles (UAV) related to the coordinated planning and control of UAVs performing surveillance missions. Performing aerial search operations is technically complicated by the requirement to recognize a search object in arbitrary conditions, which can be both simple and severe environment. The search area is limited by the UAV capabilities, so, in order to improve the efficiency of search operations, UAVs are combined into groups. An algorithm for solving the problem of object search in arbitrary conditions by a group of unmanned aircraft is proposed. The advantage of search by a group of unmanned aircraft is the coverage of the larger search area in a conventional unit of time. This paper addresses the unmanned aircraft configuration, containing both the means of collaborative flight operation and a synthetic vision system. The image obtained by the synthetic vision system is both a source of navigation information and a means which reliably determines the result of search operations. Depending on the conditions of search operations, the image obtained by the synthetic vision system may require additional processing to use as intended. A fusion algorithm is proposed, which is characterized by adaptive adjustment of parameters in each frame individually for different image fragments. Based on the results obtained, it is planned to create a new product for commercial operation of unmanned aircraft.

Methods for comparing theoretical models parameterized with field data using biological criteria and Sobol analysis

Prey–predator models are frequently developed to investigate trophic webs and to predict the population dynamics of prey and predators. However, the parameters of these models are often implemented without empirical data and may even be chosen arbitrarily. Commonly, only a few parameters are tested regarding their sensitivity and it is rare to read about the comparison between different prey–predator models (i.e. predation function structure). Here, we propose a method to compare four prey–predator models designed for two populations. We then apply this method to select the more biologically plausible one to model a simplified agricultural trophic system, including one predator compartment (the red fox Vulpes vulpes) and one prey group compartment (small mammals). These models are based on four Holling functional responses for the predation interaction and take the prey intrinsic growth rate into account through a Verhulst logistic function. Most parameters’ values (like attack rates or growth rates) were calculated from field data or based on literature review. We then used Sobol indices to conduct parameter exploration around mean parameter values to investigate and compare the model dynamics responses. Our first results showed that under our assumptions, the two most relevant models for our case study are the saturated Holling I and II models. We were also able to discriminate that among the 6 scaled parameters that vary, the model outputs are particularly sensitive to four of them (κ: saturation rate of the environment, Tr1: characteristic intrinsic decay time of the predators, Tc: characteristic growth time of the predator via the predation on the prey and λ: saturation rate of a predator’s stomach per time unit) and much less sensitive to two others (Tr2: characteristic intrinsic growth time of the prey and Ta: characteristic decay time of the prey due to the predation). These first encouraging results open the way for the next step, which will be to adapt this model construction to more complex prey–predator systems, with several predator and/or several prey compartments.

Dimensional Analysis based Prediction Model for Fuel Consumption in the Deutz Agrotrac Tractor

Background: Fuel consumption is a critical factor in the performance of an agricultural tractor. And it can be affected by numerous parameters. Farming practices is an essential aspect that affects the cost of operation and the overall efficiency of the tractor. Predictions of fuel consumption rates in tractors and the energy consumption parameters of primary tillage equipment under local conditions are therefore essential selection criteria in purchasing decisions. Methods: A prediction model for fuel usage during tillage operations was created using dimensional analysis. The model was established by incorporating experimental findings into an equation. The experiment was conducted in the El Ouracia region of Setif, Algeria in 2022/2023 crop season, with fuel usage per time unit determined through topping-up the tank method. The fuel experiment parameters were measured according to their respective standard procedures. Result: By simulating fuel usage with tillage depth, tillage width, travel speed, soil bulk density and cone index. The constant in the prediction model was obtained. This developed model has the potential to forecast the tractor fuel consumption during tillage operation.

Tutorial on MUedit: An open-source software for identifying and analysing the discharge timing of motor units from electromyographic signals

We introduce the open-source software MUedit and we describe its use for identifying the discharge timing of motor units from all types of electromyographic (EMG) signals recorded with multi-channel systems. MUedit performs EMG decomposition using a blind-source separation approach. Following this, users can display the estimated motor unit pulse trains and inspect the accuracy of the automatic detection of discharge times. When necessary, users can correct the automatic detection of discharge times and recalculate the motor unit pulse train with an updated separation vector. Here, we provide an open-source software and a tutorial that guides the user through i) the parameters and steps of the decomposition algorithm, and ii) the manual editing of motor unit pulse trains. Further, we provide simulated and experimental EMG signals recorded with grids of surface electrodes and intramuscular electrode arrays to benchmark the performance of MUedit. Finally, we discuss advantages and limitations of the blind-source separation approach for the study of motor unit behaviour during tonic muscle contractions.

Model Predictive Control With Stability Guarantee for Second-Order DC/DC Converters

This paper proposes a continuous-control-set model-predictive control (CCS-MPC) designed explicitly for second-order dc/dc converters such as the boost, buck, buck-boost, and non-inverting buck-boost converters. These converters share a bilinear dynamic structure that allows designing a generalized control. In contradistinction to the conventional finite-control-set approach, the proposed control uses a pulse-width modulation that allows a continuous control set with constant switching frequency. The modulation index's saturation is considered an inequality constraint in the optimization model. The proposed control guarantees stability in the sense of Lyapunov. This property is proven by using the passive structure of these converters. Experimental results on the four converters mentioned above show the superior performance of the proposed control in terms of robustness, offset, computation time in the central processing unit and, of course, stability.

Operative Time and Relative Value Units for Total Shoulder Arthroplasty Based on Pathology in the United States

Operative Time and Relative Value Units for Total Shoulder Arthroplasty Based on Pathology in the United States

Study of air deionization factors

The object of research is the dynamics in the concentration of air ions and suspended particles in atmospheric air and in supply-exhaust ventilation systems. An urgent task is to determine the factors and obtain quantitative data on the deionization of the atmospheric air that enters the environment where people live. Quantitative data on changes in the concentration of air ions depending on the time of day, temperature, and relative air humidity have been established. It was shown that even in the absence of significant man-made influence on the concentration of suspended particles, this indicator is at least 7000 cm-3. In the presence of wind, this indicator reaches 30000 cm-3 and higher. Measurement of the spectrum of suspended particles in the range of 0,3–6,0 μm showed that the predominant fraction is particles with sizes of about 3 μm. Studies have been conducted on changes in the concentrations of air ions in supply-exhaust ventilation systems. It was established that in the air duct made of galvanized iron, which has a length of 16 m, the concentration of negative air ions is reduced by 67 %, and positive by 78 %. Laboratory studies of air deionization in air ducts made of different materials were carried out. There is significant air deionization in metal and cardboard ducts while it is absent in wooden ducts. This indicates the electrical nature of deionization. A calculation method for forecasting the aero-ionic mode of premises, taking into account the factors of air deionization, is proposed. For rooms with supply-exhaust ventilation, a calculation apparatus is proposed taking into account the air exchange rate (the number of complete air changes per unit of time). The results make it possible to choose the required performance of artificial air ionization devices for normalizing the aero-ionic regimes in the premises

Physical performance strongly predicts all-cause mortality risk in a real-world population of older diabetic patients: machine learning approach for mortality risk stratification.

Prognostic risk stratification in older adults with type 2 diabetes (T2D) is important for guiding decisions concerning advance care planning. A retrospective longitudinal study was conducted in a real-world sample of older diabetic patients afferent to the outpatient facilities of the Diabetology Unit of the IRCCS INRCA Hospital of Ancona (Italy). A total of 1,001 T2D patients aged more than 70 years were consecutively evaluated by a multidimensional geriatric assessment, including physical performance evaluated using the Short Physical Performance Battery (SPPB). The mortality was assessed during a 5-year follow-up. We used the automatic machine-learning (AutoML) JADBio platform to identify parsimonious mathematical models for risk stratification. Of 977 subjects included in the T2D cohort, the mean age was 76.5 (SD: 4.5) years and 454 (46.5%) were men. The mean follow-up time was 53.3 (SD:15.8) months, and 209 (21.4%) patients died by the end of the follow-up. The JADBio AutoML final model included age, sex, SPPB, chronic kidney disease, myocardial ischemia, peripheral artery disease, neuropathy, and myocardial infarction. The bootstrap-corrected concordance index (c-index) for the final model was 0.726 (95% CI: 0.687-0.763) with SPPB ranked as the most important predictor. Based on the penalized Cox regression model, the risk of death per unit of time for a subject with an SPPB score lower than five points was 3.35 times that for a subject with a score higher than eight points (P-value <0.001). Assessment of physical performance needs to be implemented in clinical practice for risk stratification of T2D older patients.

Development of a Benchmark for Thermal Striping in Gas-Cooled Fast Reactors

This paper presents the development of a benchmark for predicting thermal striping through simulation. This work utilized large eddy simulation and will be used to benchmark future models. The testing domain was created using both the STRUCT and the Reynolds-averaged Navier-Stokes turbulence models and is based on an earlier design of the General Atomics Fast Modular Reactor upper plenum. The plenum features two adjacent, identical hexagonal bundles each with a center-placed axial rod drive, with a hot left coolant stream and a cold right coolant stream. The simulation solves the nondimensional Navier-Stokes equations, with temperature accounted as a passive scalar. First- and second-order flow statistics were obtained after 600 convective time units of averaging. The first-order statistics reveal that the hot jet is damped by a recirculatory flow from the near wall. At the same location, the second-order statistics show strong oscillations both in velocity and temperature. The power spectral density was utilized to determine that a low-frequency oscillation occurs here that is within the range of interest for thermal striping. Furthermore, proper orthogonal decomposition was used to identify coherent structures that confirm the oscillatory behavior, indicative of thermal striping. Overall, this benchmark can aid in the development of future models for predicting thermal striping in nuclear reactors, potentially leading to improved reactor safety and performance.

Phase transitions of civil unrest across countries and time

Phase transitions, characterized by abrupt shifts between macroscopic patterns of organization, are ubiquitous in complex systems. Despite considerable research in the physical and natural sciences, the empirical study of this phenomenon in societal systems is relatively underdeveloped. The goal of this study is to explore whether the dynamics of collective civil unrest can be plausibly characterized as a sequence of recurrent phase shifts, with each phase having measurable and identifiable latent characteristics. Building on previous efforts to characterize civil unrest as a self-organized critical system, we introduce a macro-level statistical model of civil unrest and evaluate its plausibility using a comprehensive dataset of civil unrest events in 170 countries from 1946 to 2017. Our findings demonstrate that the macro-level phase model effectively captures the characteristics of civil unrest data from diverse countries globally and that universal mechanisms may underlie certain aspects of the dynamics of civil unrest. We also introduce a scale to quantify a country’s long-term unrest per unit of time and show that civil unrest events tend to cluster geographically, with the magnitude of civil unrest concentrated in specific regions. Our approach has the potential to identify and measure phase transitions in various collective human phenomena beyond civil unrest, contributing to a better understanding of complex social systems.

Complexity growth patterns in the Big History: Preliminary results of a quantitative analysis

The paper presents preliminary results of a quantitative analysis of two patterns of complexity growth in the Big History – decelerating universal (cosmic) evolutionary development evidenced in the Universe for a few billions of years after the Big Bang (around 13.8 billion BP) and accelerating global (biosocial) evolutionary development observed for about 4 billion years on the planet Earth since the emergence of life on it and until the early 1970s. It is shown that the first pattern can be described with an astonishing accuracy (R2 = 0.999996) by the following equation: y = C1/(t-t1*), where y is the rate of the universal complexity growth (measured as a number of phase transitions [accompanied by the growth of complexity] per a unit of time), C1 is a constant, and t-t1* is the time since the Big Bang Singularity (t1*~13.8 billion years BP). In the meantime, it was earlier shown that the second pattern could be described with an almost as high accuracy (R2 = 0.9989 to 0.9991) by the following equation: y = C2/(t2*-t), where y is the rate of accelerating global (biosocial) evolutionary development, C2 is another constant, and t2*-t is the time till the 21st century Singularity (t2*, estimated to be around 2027, or 2029 CE). Thus, the post-Big-Bang hyperbolic decrease of universal complexity growth rate and the hyperbolic increase of the growth rate of global complexity in the last 4 billion years proceeded following the same law. We are dealing here with a perfect symmetry: (1) the rate of the universal (cosmic) complexity growth decreases when we move from the Big Bang Singularity, whereas the rate of the global complexity growth increase when we approach the 21st century Singularity; (2) more specifically, as the time since the Big Bang Singularity increases n times, the universal (cosmic) complexity growth rate decreases the same n times, whereas when the time till the 21st century Singularity decreased n times, the global complexity growth rate increased the same n times. A somehow more complex symmetry is observed as regards the interaction between energy dynamics and complexity growth within both processes. The implications of the symmetry of both patterns are discussed.

Homogeneous crystallization in four-dimensional Lennard-Jones liquids.

We observe homogeneous crystallization in simulated high-dimensional (d>3) liquids that follow physically realistic dynamics and have system sizes that are large enough to eliminate the possibility that crystallization was induced by the periodic boundary conditions. Supercooled four-dimensional (4D) Lennard-Jones (LJ) liquids maintained at zero pressure and constant temperatures 0.59<T<0.63 crystallized within ∼2×10^{4}τ, where τ is the LJ time unit. Weeks-Chandler-Andersen (WCA) liquids that were maintained at the same densities and temperatures at which their LJ counterparts nucleated did not crystallize even after 2.5×10^{5}τ, showing that the presence of long-ranged attractive interactions dramatically speeds up 4D crystallization, much as it does in 3D. On the other hand, the overlap of the liquid and crystalline phases' local-bond-order distributions is smaller for LJ systems than for WCA systems, which is the opposite of the 3D trend. This implies that the widely accepted hypothesis that increasing geometrical frustration rapidly suppresses crystallization as the spatial dimension d increases is only generally valid in the absence of attractive interparticle forces.

BNQDs and Fe2O3QDs co-doped in porous g-C3N4 for accelerating photogenerated electron migration and enhancing photo-Fenton catalysis efficiency

With the maturity of advanced oxidation processes, photo-Fenton synergistic catalytic technology, as one of them, has become an irreplaceable strategy in environmental treatment and other fields. However, this technology suffers from drawbacks such as facile recombination of electron-hole pairs (e-/h+), low conversion efficiency between Fe3+ and Fe2+, and limited active sites. To address these issues, this study constructs a photo-Fenton synergistic system based on porous g-C3N4 (FBNCN) modified with BNQDs and Fe2O3QDs. Among them, the porous g-C3N4 provides more active sites and larger quantum dot anchoring space for the catalytic reaction. The introduction of the BNQDs effectively traps the hole (h+), reduces e-/h+ recombination, facilitates the photo-generated electrons leap, and accelerates charge transfer, while the anchoring of Fe2O3QDs enables efficient the migration of active sites and charges. This results in improved conversion efficiency between Fe3+ and Fe2+, leading to enhanced generation of ·O2- and ·OH species that exhibit excellent visible-light-catalyzed oxidation ability. Moreover, remarkable degradation efficiency was achieved for antibiotic organic pollutants (tetracycline hydrochloride, chlortetracycline hydrochloride, norfloxacin, amoxicillin) per unit of time using this catalyst system, thus providing a new method for antibiotic organic pollutant degradation. In-situ XPS technique was used to analyze the movement direction of the photogenerated charges of the composite photocatalytic materials and reveal the degradation mechanism under the synergistic system.

Evolution in Liver trauma management: A single centre experience

OBJECTIVES Liver trauma is common and can be treated non-operatively, through radiological embolisation, or surgically. Non-operative management (NOM) is preferred when possible, but specific criteria remain unclear. This retrospective study at a level I trauma centre assessed the evolution and outcomes of liver injury management over more than 20 years. METHODS Data from January 1996 to June 2020 were analysed for liver trauma cases. Variables were evaluated, including the type of injury, diagnostic modalities, liver injury grade, transfer from other hospitals, treatment type and length of hospital stay. Outcomes were assessed using soft (hospitalisation time and intensive care unit stay) and hard (mortality) endpoints. RESULTS In total 406 patients were analysed, of which 375 (92.4%) had a blunt and 31 (7.6%) a penetrating liver trauma. Approximately one-third (31.2%) were hemodynamically unstable, although 78.8% had low-grade liver lesions. The initial treatment was non-operative in 72.9% of the patients (68.5% conservative, 4.4% interventional radiology). Blunt trauma was treated by surgery in 23.2% of the patients, while 74.2% in case of penetrating trauma. Overall mortality was 11.1% including death caused by associated lesions. The 24-hour mortality was 5.7%. Indication for surgical treatment was determined by hemodynamic instability, high grade liver lesion, penetrating trauma and associated lesions. CONCLUSIONS Although the role of surgery in liver trauma management has strongly diminished over recent decades, hemodynamically unstable patients, high-grade lesions, penetrating trauma and severe associated lesions are the main indications for surgery. In other situations, NOM by full conservative therapy or radiological embolisation seems effective.

Implications of husking process on the nutritional composition of sorghum grains: diverse varieties and regions

SummarySorghum, known for its nutritional value, health benefits and gluten‐free status, is now widely produced and suitable for human consumption in developed regions due to advancements in sorghum research and processing techniques. The research looked at how well the husking fraction time unit (HFTU) technique worked by examining its effects on the nutritional value of three varieties of sorghum grain. The efficiency of the husking process was assessed at 87% for concentrated and redistributed nutritional contents and 60% for variation of mineral contents based on bran/ endosperm. The technique reduced the T.K.W. compared to whole grain to the endosperm (grits). Moreover, the redistribution of the crude protein % showed the precision of the HFTU procedure by demonstrating an average of 26.6% as a variation ratio of the bran/endosperm in the data set. Contrary to the content of the total dietary fibre content, for example, the variation of TDF % attributed to bran/endosperm was 10.9%. On the other hand, the average ash % of whole grains (hummer) and husked products (TM05C) was increased by 33.2% based on averages of 1.5% and 2.1%, respectively. Accordingly, it was approved that the HFTU procedure effectively separated the endosperm (grits) and bran. This study also found that minerals such as Ca, Cu, Fe, K, Mg, Mn, Na, P, S and Zn changed over 30‐to‐80‐time units by 29%, 13%, 8%, 4%, 17%, 18%, 1%, 13%, 6% and 12% in the bran and endosperm. The HFTU process has influenced the colour attributes of variation sorghum varieties, particularly within a time scale of 80 (S) units. The research revealed that the husking technique substantially impacted the different sorghum grain varieties’ nutritional composition and colour properties. The method can be useful for developers in enhancing sorghum grain products’ nutritional properties attributed to various varieties and regions, allowing them to provide high nutritional quality sourced from sustainable products.

Mixed Variable Parameter Energy Storage-Assisted Frequency Support Strategy

With the continuous increase in the installed capacity of new energy systems, the impact of power shocks on grid frequency is becoming more significant, seriously affecting the stability of the grid and thermal power units. For this reason, a mixed variable parameter energy storage-assisted frequency support control method is proposed. This method introduces an integral control mode based on the existing control mode and forms a co-ordinated control mode. The impact of the switching point of the mixed control mode is analyzed, and a new mode switching method is used. The model adjusts the frequency regulation parameters according to the different states of the grid frequency, making the frequency regulation more efficient. Finally, a frequency regulation model that integrates various improvement methods is built, and a 10 min continuous load disturbance is applied to compare and verify the frequency regulation performance of the model as a whole. The results indicate that the proposed control method can significantly improve the quality of grid frequency regulation, reduce the frequency deviation amplitude to 0.00096 p.u., reduce the participation time of thermal power units to 190.8393 s, and reduce the peak output to 0.1934 MW, demonstrating its engineering feasibility.

Monitoring a sequence of Bernoulli random variables subject to gradual changes in the success rates where the success rates are unknown

We look at a sequence of Bernoulli random variables where the success rates change from θ 1 to θ 2. We will assume that both the success rates before and after the change are unknown but increasing. We assume that this change does not happen abruptly but gradually over a period of time η where η is known. We calculate the probability that the change has started and completed. We also look at optimal stopping rules assuming that there is a cost for a false alarm and a cost per time unit to stop late.

Characterization of Antibiotic Resistance in Select Tertiary Hospitals in Uganda: An Evaluation of 2020 to 2023 Routine Surveillance Data.

Antimicrobial resistance (AMR) is a public health concern in Uganda. We sought to conduct an extended profiling of AMR burden at selected Ugandan tertiary hospitals. We analyzed routine surveillance data collected between October 2020 and March 2023 from 10 tertiary hospitals. The analysis was stratified according to the hospital unit, age, gender, specimen type, and time. Up to 2754 isolates were recovered, primarily from pus: 1443 (52.4%); urine: 1035 (37.6%); and blood: 245 (8.9%). Most pathogens were Staphylococcus aureus, 1020 (37%), Escherichia coli, 808 (29.3%), and Klebsiella spp., 200 (7.3%). Only 28% of Escherichia coli and 42% of the other Enterobacterales were susceptible to ceftriaxone, while only 44% of Staphylococcus aureus were susceptible to methicillin (56% were MRSA). Enterococcus spp. susceptibility to vancomycin was 72%. The 5-24-year-old had 8% lower ampicillin susceptibility than the >65-year-old, while the 25-44-year-old had 8% lower ciprofloxacin susceptibility than the >65-year-old. The 0-4-year-old had 8% higher ciprofloxacin susceptibility. Only erythromycin susceptibility varied by sex, being higher in males. Escherichia coli ciprofloxacin susceptibility in blood (57%) was higher than in urine (39%) or pus (28%), as was ceftriaxone susceptibility in blood (44%) versus urine (34%) or pus (14%). Klebsiella spp. susceptibility to ciprofloxacin and meropenem decreased by 55% and 47%, respectively, during the evaluation period. During the same period, Escherichia coli ciprofloxacin susceptibility decreased by 40%, while Staphylococcus aureus gentamicin susceptibility decreased by 37%. Resistance was high across the Access and Watch antibiotic categories, varying with time, age, sex, specimen type, and hospital unit. Effective antimicrobial stewardship targeted at the critical AMR drivers is urgently needed.

Hydrological time series prediction based on IWOA-ALSTM

The prediction of hydrological time series is of great significance for developing flood and drought prevention approaches and is an important component in research on smart water resources. The nonlinear characteristics of hydrological time series are important factors affecting the accuracy of predictions. To enhance the prediction of the nonlinear component in hydrological time series, we employed an improved whale optimisation algorithm (IWOA) to optimise an attention-based long short-term memory (ALSTM) network. The proposed model is termed IWOA-ALSTM. Specifically, we introduced an attention mechanism between two LSTM layers, enabling adaptive focus on distinct features within each time unit to gather information pertaining to a hydrological time series. Furthermore, given the critical impact of the model hyperparameter configuration on the prediction accuracy and operational efficiency, the proposed improved whale optimisation algorithm facilitates the discovery of optimal hyperparameters for the ALSTM model. In this work, we used nonlinear water level information obtained from Hankou station as experimental data. The results of this model were compared with those of genetic algorithms, particle swarm optimisation algorithms and whale optimisation algorithms. The experiments were conducted using five evaluation metrics, namely, the RMSE, MAE, NSE, SI and DR. The results show that the IWOA is effective at optimising the ALSTM and significantly improves the prediction accuracy of nonlinear hydrological time series.