Optimal Strategy Research Articles

Optimal strategy to reduce energy waste in an electricity distribution network through direct/indirect bulk load control

In recent decades, the ever-increasing demand for electricity in large cities is leading the electricity distribution network (EDN) to an operational state of fatigue, especially at peak load times. In this context, load congestion, technical losses, and voltage deviations across the EDN can contribute to the high waste of electricity as well as to the worsening of the supply service. To face this problem, this paper proposes a mixed integer linear programming (MILP) model that aims to reshape the demand profile (i.e., load reduction in peak periods without load rebound in the remaining periods of the day) of total consumers while the voltage deviations and technical losses are minimized. In the proposed model, the demand profile reshaping is carried out through direct (DC) and indirect (IC) bulk control of residential, commercial, and industrial loads, while the load factor (LF), i.e., indicator related to the efficient use of electricity, is improved. Due to the scheduling of these loads at certain times of the day, the occurrence of voltage deviations and technical losses can be mitigated by the efficient control of capacitor banks (CBs). To corroborate the applicability of the proposed MILP model, the 33-node IEEE test system was used. The results show the technical and economic gains for the distribution company (DISCO) and the total number of consumers.

A target defence‐intrusion game with considering the obstructive effect of target

AbstractThis paper considers the problem of a defender agent to guard the target area being attacked by a hostile agent. There are two different agents‐intruder and defender here. The purpose of the defender is to prevent the intruder from approaching the target and if possible, catch the intruder. As the guardian object of the defender, the target area also obstructs its free movement. Therefore, a new geometric method is proposed to solve the problem. Firstly, the winning zones are constructed for the agents using two different methods. When the defender's initial position is in the defender's winning zone, the defender can capture the intruder. When the initial position of the defender is in the winning zone of the intruder, the intruder can successfully attack the target. Subsequently, a method is proposed for determining the dominance region boundary under the influence of target obstruction. Also, the winner can be ascertained by observing whether the dominance region boundary intersects the target area. The optimal strategy is then given according to the different payoff functions. Finally, some examples show the effectiveness of the method. In addition, the conditions and limitations for applying this method to other convex targets are provided.

The dynamics of a bicycle on a pump track – first results on modeling and optimal control

Abstract We investigate the dynamics of a bicycle on an uneven mountain bike track split into straight sections with small jumps (kickers) and banked corners. A basic model of the interaction of bicycle and rider proposed and used to derive equations of motion, which capture the possibilities to accelerate the bicycle without pedaling. Since this is a first approach to the problem, only corners connected by straight lines are considered to compute optimal riding strategies. The simulation is validated with experimental data obtained on a real pump track. It is demonstrated that the model effectively captures the longitudinal bike acceleration resulting from the relative vertical motion between the rider’s upper body and the bicycle. Our numerical results are in good analogy with real rider’s actions on similar tracks.

Experimental investigation on the open cathode air-cooled proton exchange membrane fuel cells: Optimum operating parameters and control strategies

Operating parameters and control strategies are crucial for the performance of open cathode air-cooled proton exchange membrane fuel cells. In present study, effects of hydrogen pressure, anode purging ratio and stack temperature on an open cathode air-cooled PEMFC with 40 single cells are experimentally explored. Comprehensive evaluations of operating parameters and control strategies are adopted from multiple aspects including output performance, stability, hydrogen consumption, and system efficiency. The results show that an anode pressure of 60–70 kPa and a 4% purging ratio can achieve not exceeding 5% ripple coefficient and not less than 35% system efficiency, and the optimum stack temperature is proved to be 54–60 °C. Adaptive purging strategies and temperature control strategies that vary with current are summarized which can be used for programming applications. Finally, these control strategies are executed under simulated loads to observe stack’s dynamic response and confirmed to maintain stable operation of the stack.

A quasi-experimental evaluation of the association between implementation of Quality-Based Procedures funding for hip fractures and improvements in processes and outcomes for hip fracture patients in Ontario: an interrupted time series analysis.

In 2013, Ontario introduced a patient-based funding model for hip fracture care (Quality-Based Procedures [QBP]). The association of QBP implementation with changes in processes and outcomes has not been evaluated. We conducted a quasi-experimental study using linked health data for adult hip fractures as an interrupted time series. The pre-QBP period was from 2008 to 2012 and the post-QBP period was from 2014 to 2018; 2013 was excluded as a wash-in period. We used segmented regression analyses to estimate the association of QBP implementation with changes in processes (surgery in less than two days from admission, use of echocardiography, use of nerve blocks, and provision of geriatric care) and clinical outcomes (90-day mortality, 90-day readmissions, length of stay, and days alive at home). We estimated the immediate (level) change, trend (slope) postimplementation, and total counterfactual differences. Sensitivity analyses included case-mix adjustment and stratification by hospital type and procedure. We identified 45,500 patients in the pre-QBP period and 41,256 patients in the post-QBP period. There was a significant total counterfactual increase in the use of nerve blocks (11.1%; 95% confidence interval [CI], 6.2 to 16.0) and a decrease in the use of echocardiography (-2.5%; 95% CI, -3.7 to -1.3) after QBP implementation. The implementation of QBP was not associated with a clinically or statistically meaningful change in 90-day mortality, 90-day readmission, length of stay, or number of days alive at home. Evaluation of the QBP program is crucial to inform ongoing and future changes to policy and funding for hip fracture care. The introduction of the QBP Hip Fracture program, supported by evidence-based recommendations, was associated with improved application of some evidence-based processes of care but no changes in clinical outcomes. There is a need for ongoing development and evaluation of funding models to identify optimal strategies to improve the value and outcomes of hip fracture care. Open Science Framework ( https://osf.io/2938h/ ); first posted 13 June 2022.

Clinical, epidemiological, and therapeutic hallmarks of pyoderma gangrenosum: a case series of 35 patients.

Over the past few decades, advances in medical research and diagnostic tools have shed light on some aspects of pyoderma gangrenosum (PG). Nevertheless, the multifactorial etiology, pathogenesis, and optimal management strategies for PG need to be further investigated. To address these knowledge gaps and contribute to a better understanding of this complex dermatological disorder, we collected epidemiological, clinical, and therapeutic aspects of a case series of PG patients occurring in our department over the past 10 years. We performed a single-centered, retrospective, observational study analyzing all cases with a diagnosis of PG observed at the Dermatology clinic of the Fondazione Policlinico A. Gemelli IRCCS Catholic Universityfrom January 1, 2013, to January 1, 2023. For each case, we retrieved demographic data, the presence of other skin and systemic conditions, and the histopathological and clinical characteristics of PG, such as clinical variant, number of lesions, disease localization, previous therapy, response to treatment, and occurrence of relapse. We included 35 patients, 22 females and 13 males with a mean age of 40.0 years. Twenty patients (57.1%) had multiple localizations of disease, and the most commonly involved site was the lower limbs (85.7%). The lesions were mainly associated with inflammatory bowel diseases (51.4%) and hidradenitis suppurativa (37.1%). Clinical resolution with complete re-epithelialization was achieved in 25 patients (71.4%) with an average time of 20.8 months. On average, patients who underwent therapy with biological drugs had better outcomes. PG is a severe, rare, and pleomorphic disease associated with a broad spectrum of conditions. Corticosteroids remain the primary first-line approach for severe forms, but using biological immunosuppressants is promising.

Combining Gasoline Compression Ignition and Powertrain Hybridization for Long-Haul Applications

Gasoline compression ignition (GCI) combustion was demonstrated to be an effective combustion concept to achieve high brake thermal efficiency with low-reactivity fuels while offering improved NOx–soot trade-off. Nevertheless, future greenhouse gas regulations still challenge the heavy-duty transportation sector on both engine and vehicle basis. Hybridization is a possible solution in this scenario, allowing the avoidance of low-efficiency conditions and energy recovery during regenerative braking, improving overall vehicle efficiency. In this sense, this investigation proposes a detailed analysis to understand the optimum hybridization strategy to be used together with GCI to simultaneously harness low pollutant and CO2 emissions. For that, different hybrid architectures were defined in GT Drive (Mild hybrid 48 V P0 and P2 and full Hybrid P2 500 V) and submitted to 15 different use cases, constituted by five normative and real-driving conditions from the US, China, India, and Europe and three different payloads. Results showed that all hybridization strategies could provide fuel savings benefits to some extent. Nonetheless, usage profile is a dominant factor to be accounted for, benefiting specific hybrid powertrains. For instance, P0 and P2 48 V could provide similar savings as P2 500 V, where regenerative braking is limited. Nonetheless, P2 500 V is a superior powertrain if more demanding cycles are considered, allowing it to drive and recuperate energy without exceeding the Crate limitations of the battery.

Analysis of statistical uncertainties of non-contact temperature and emissivity measurements in the optical and near infrared ranges

The aim of this report is the analysis of the uncertainties of non-contact measurement of temperature and emissivity determined by the least sum of squares (LSS) method. Analytical expressions are obtained for the uncertainties of the temperature T and the emissivity ε by three methods: (1) linear regression using the Wien approximation, (2) non-linear regression with covariance matrix calculation using the Planck’s equation, and (3) hybrid method that combines linear and non-linear regression methods. It was found that the better the condition for the Wien’s approximation is fulfilled, the worse the accuracy of the emissivity measurement compared to the accuracy of the temperature measurement. The new optimal strategy is proposed to determine the T and the emissivity ε for non-contact measurements. It consists of three steps: (1) the temperature of the radiating body is found by the Wien approximation, TW; (2) the obtained value TW is used as an initial approximation for one-dimensional “hybrid” minimization. Minimization is carried out by one of the numerical methods of one-dimensional minimization. As a result, the values of ε0 and T0 are found at with the sum of the squared residuals, S0, reaches a minimum; (3) Measurement uncertainties are estimated using the covariance matrix method.

Parametric design of photovoltaic louver integrated shading devices for west facade windows of office buildings in central China

ABSTRACT In order to improve the shading performance and power generation effect of Photovoltaic shading integrated devices (PVSDs) on the west facade of buildings in China, a multi-objective optimization design method is proposed in this paper. Taking a west-facing office building in Zhengzhou, Henan Province, as an example, a parametric model of photovoltaic (PV) louvers for windows on the west facade is established, and parametric design research is carried out on the energy-saving potential of PV louver shading systems. Based on the optimization objectives of power generation of PV louvers, indoor thermal discomfort hours, building cooling load and lighting energy consumption, the performance of the west facade office with PVSD under different design strategies was simulated, and the optimal design strategy was determined according to the preference of decision makers. Compared with the basic type without a non-shading model, the indoor lighting energy consumption of the optimized west facade PVSD is slightly increased. However, overall performance is improved, with a 35% reduction in cooling load, a decrease of 804.59 kWh in total energy consumption, and a shortened summer thermal discomfort time of 404 hours. The power generation of PV louvers can replace 46% of the total energy consumption of the room. The results show that the installation of PVSD on the west facade window is important for alleviating the overheating inside the room and improving the energy-saving and power generation potential of the room.

Joint optimization of component reassignment and working intensity adjusting strategy for multi-state systems with periodic inspection in a shock environment

For some engineering systems performing a mission with long duration, the component positions and working intensity can be dynamically adjusted to improve the efficiency of mission completion and system reliability. Motivated by this reality, a joint strategy of component reassignment and working intensity adjusting is proposed for a multi-component system. Components at different positions can be functionally exchanged. When at least one component fails completely, the system fails. The system operates under a shock environment and the probability that a shock is valid to a component is affected by its position and working intensity. The system can complete more tasks per unit time in a higher working intensity, but the probability that a shock is valid to a component is also larger. The mission is divided into multiple phases, and the action of component reassignment and working intensity adjusting needs to be decided at the beginning of each phase. A Markov decision process is constructed and the optimal mission phase number and strategy are obtained by a finite stage backward recursive iterative algorithm. An Unmanned Aerial Vehicle (UAV) swarm performing an emergency rescue mission is taken as an example to verify the effectiveness of the proposed joint strategy.

Real-time operation strategy of virtual power plants with optimal power disaggregation among heterogeneous resources

The virtual power plant (VPP) can aggregate flexible resources on the demand side to provide frequency regulation for the grid, helping address the supply–demand balance challenges. When deploying regulation, the VPP disaggregates the requested power adjustment in real time among its internal heterogeneous resources. Achieving optimal power disaggregation in this process is challenging due to the temporal coupling characteristics of the resources, the uncertain regulation signals, and the requirement for fast response. Therefore, existing research relies on heuristic methods, such as proportional disaggregation, and fails to leverage the heterogeneity of multiple resources. Here, we propose an optimal operation strategy for VPPs to provide regulation, exploiting the complementary characteristics of heterogeneous resources by prioritising the use of low-cost resources while considering temporal coupling. To reduce the computational overhead of online deployment, we further propose a fast disaggregation algorithm to eliminate the reliance on optimisation solvers. We conducted case studies on the operation of a VPP composed of resources including thermostatically controlled loads and industrial production processes. The results verified the reduced operation cost and increased profit of the VPP under the proposed strategy, with only milliseconds of online computation time. We believe that our work can help better exploit demand-side flexibility.

The effect of short-form video content, speed, and proportion on visual attention and subjective perception in online food delivery menu interfaces

Given the rising popularity of utilizing short-form videos as visual cues, employing short-form videos to showcase food visual information in online food delivery menu interfaces could be a promising approach. However, it remains unclear about the effect of short-form video attributes on visual attention and perception of online food delivery consumers. In an experimental study with 36 participants, we combined eye-tracking technology and a perceived quality scale to assess consumers’ visual attention and subjective perception while they performed simulated ordering tasks on designed menu interfaces featuring different video contents, speeds, and proportions. Our results indicated that videos showcasing food tasting and food plating garnered more frequent visual attention and better ordering experience, respectively. Conversely, videos showcasing food cooking led to higher cognitive effort and received worse assessment. Furthermore, we found no significant evidence linking faster video speeds to increased cognitive effort, despite a slightly longer fixation duration in fast-speed videos. Besides, large video formats attracted more visual attention and created better user experiences compared to small formats, with medium formats also performing well in terms of subjective perception. These insights shed light on the optimal strategies for implementing short-form video presentations on online food delivery platforms, thus contributing to the development of user-friendly online menu interfaces for consumers.

Optimal antithrombotic strategy in patients with atrial fibrillation beyond 1 year after drug-eluting stent implantation: Design and rationale of the randomized ADAPT AF-DES trial

BackgroundBoth anticoagulation and antiplatelet therapies are recommended after percutaneous coronary intervention (PCI) in patients with atrial fibrillation (AF). Although contemporary guidelines recommend discontinuation of antiplatelet therapy 1 year after drug-eluting stent (DES) implantation due to excessive bleeding risk, supporting randomized trials are still lacking. MethodsThe ADAPT AF-DES trial is a multicenter, prospective, open-label, randomized, non-inferiority trial, enrolling 960 patients with AF with a CHA2DS2-VASc score > 1, who underwent PCI with DES implantation at least 12 months before enrollment. Eligible patients are randomly assigned to receive either non-vitamin K antagonist oral anticoagulant (NOAC) monotherapy or NOAC plus clopidogrel combination therapy. The primary outcome is net adverse clinical event (NACE) at 1 year after randomization, defined as a composite of all-cause death, myocardial infarction, stent thrombosis, stroke, systemic embolism, and major or clinically relevant non-major bleeding, as defined by the International Society on Thrombosis and Hemostasis criteria. We hypothesize that NOAC monotherapy would be non-inferior to NOAC plus clopidogrel combination therapy for NACE in patients with AF beyond 12 months after DES implantation. ConclusionsThe ADAPT AF-DES trial will evaluate the efficacy and safety of NOAC monotherapy versus NOAC plus clopidogrel combination therapy in patients with AF beyond 12 months after PCI with DES implantation. The ADAPT AF-DES trial will provide robust evidence for an optimal antithrombotic strategy in patients with AF after DES implantation. Clinical trial registrationhttps://www.clinicaltrials.gov. Unique identifier: NCT04250116.

Unraveling psychological dilemma among miners in the context of low-carbon transformation: an ISM-MICMAC approach

Purpose With the rapid low-carbon transformation in China, the industrial approach and labor structure of mining enterprises are undergoing constant changes, leading to an increasing psychological dilemma faced by coal miners. This study aims to reveal the relationship and mechanism of factors influencing the psychological dilemma of miners, and to provide optimal intervention strategies for the safety and sustainable development of employees and enterprises. Design/methodology/approach To effectively address the complex issue of the psychological dilemma faced by miners, this study identifies and constructs five-dimensional elements, comprising 20 indicators, that influence psychological dilemmas. The relational mechanism of action of factors influencing psychological dilemma was then elucidated using an integration of interpretive structural modeling and cross-impact matrix multiplication. Findings Industry dilemma perception is a “direct” factor with dependent attributes. The perceptions of management response and relationship dilemmas are “root” factors with driving attributes. Change adaptation dilemma perception is a “susceptibility” factor with linkage attributes. Work dilemma perception is a “blunt” factor with both dependent and autonomous attributes. Originality/value The aforementioned findings offer a critical theoretical and practical foundation for developing systematic and cascading intervention strategies to address the psychological dilemma mining enterprises face, which contributes to advancing a high-quality coal industry and efficient energy development.

Optimal extent of lymph node dissection for high-risk gastric cancer stratified by a national clinical database risk calculator.

For patients with gastric cancer, a well-balanced treatment that considers both oncological aspects and surgical risk is demanded. This study aimed to explore the optimal extent of lymph node dissection (LND) for patients with gastric cancer according to surgical risk, stratified by the risk calculator system produced by the Japan National Clinical Database (NCD). We retrospectively evaluated 187 patients who underwent radical gastrectomy for gastric cancer. Using the median predicted anastomotic leak rate obtained by the NCD risk calculator as the cutoff value, we classified 97 and 90 patients as having high and low risks, respectively. In low-risk patients, although limited LND reduced the postoperative intraabdominal infectious complications (IAIC), multivariate analysis revealed standard LND as an independent prognostic factor that improved Relapse-free survival (RFS). In high-risk patients, the rates of postoperative IAIC and RFS were similar between standard and limited LND. Pancreatic fistula was not observed in the limited dissection group. Limited LND might be the optimal treatment strategy for patients with gastric cancer with high surgical risk.

Planning for the optimal vaccination sequence in the context of a population-stratified model

We explore strategies for optimally controlling the pandemic through practical vaccination planning across different subpopulations, with the aiming of striking a balance between minimizing mortalities and conserving vaccines. To achieve this objective, the total population is categorized into four subpopulations: health workers, young individuals, middle-aged individuals, and the elderly, based on immunity and exposure risk. We assume a heterogeneous pattern of social contacts among these subpopulations. Accordingly, we formulate a population-stratified SPMILHRD model with 32 compartments that accounts for different statuses of detection and symptoms to define the epidemic dynamics. Numerical simulations demonstrate a staged optimization-based, population-stratified vaccination approach, where health workers, the middle-aged, the elderly, and the young receive priority in succession. The analysis reveals that our optimal vaccination control strategy can significantly reduce the number of infections, including fatalities, compared to scenarios involving proportional policies or no control in the numerical experiment. It has demonstrated that well-designed vaccination planning could substantially curb dissemination and reduce mortality. The findings of this study are instructive for the potential implementation of future vaccine administration.

Comparison of clinical and radiological outcomes for the anterior and medial approaches to open reduction in the treatment of bilateral developmental dysplasia of the hip: a systematic review protocol.

Developmental dysplasia of the hip (DDH) affects 1-3% of newborns and 20% of cases are bilateral. The optimal surgical management strategy for patients with bilateral DDH who fail bracing, closed reduction or present too late for these methods to be used is unclear. There are proponents of both medial approach open reduction (MAOR) and anterior approach open reduction (AOR); however, there is little evidence to inform this debate. We will perform a systematic review designed according to the Preferred Reporting Items for Systematic Review and Meta-Analysis Protocol. We will search the medical and scientific databases including the grey and difficult to locate literature. The Medical Subject Headings "developmental dysplasia of the hip", "congenital dysplasia of the hip", "congenital hip dislocation", "developmental hip dislocation", and their abbreviations, "DDH" and "CDH" will be used, along with the qualifier "bilateral". Reviewers will independently screen records for inclusion and then independently extract dataon study design, population characteristics, details of operative intervention and outcomes from the selected records. Data will be synthesised and a meta-analysis performed if possible. If not possible we will analyse data according to Systematic Review without Meta-Analysis guidance. All studies will be assessed for risk of bias. For each outcome measure a summary of findings will be presented in a table with the overall quality of the recommendation assessed using the Grading of Recommendations Assessment Development and Evaluation approach. The decision to perform MAOR or AOR in patients with bilateral DDH who have failed conservative management is not well informed by the current literature. High-quality, comparative studies are exceptionally challenging to perform for this patient population and likely to be extremely uncommon. A systematic review provides the best opportunity to deliver the highest possible quality of evidence for bilateral DDH surgical management. The protocol has been registered in the International Prospective Register of Systematic Reviews (PROSPERO ID CRD42022362325).

Diagnostic utility of whole-body computed tomography/pan-scan in trauma: a systematic review and meta-analysis study.

Trauma is a significant cause of mortality and morbidity. It is crucial to diagnose trauma patients quickly to provide effective treatment interventions in such conditions. Whole-body computed tomography (WBCT)/pan-scan is an imaging technique that enables a faster and more efficient diagnosis for polytrauma patients. The purpose of this systematic review and meta-analysis is to evaluate the efficacy of WBCT in diagnosing injuries in polytrauma patients. We will also assess its impact on the mortality rate and length of hospital stay among trauma centers between patients who underwent WBCT and those who did not (non-WBCT). Twenty-seven studies meeting our inclusion criteria were selected among PubMed, Scopus, Web of Science, and Google Scholar. The criteria were centered on the significance of WBCT/pan-scan application in trauma patients. Stata version 15 was used to perform statistical analysis on the data. The authors have also used I2 statistics to evaluate heterogeneity. Egger and Begg's tests were performed to rule out any publication bias. Total of twenty-seven studies including 68,838 trauma patients with a mean age of 45.0 ± 24.7years were selected. Motor vehicle collisions were the most common cause of blunt injuries (80.0%). Head, neck, and face injuries were diagnosed in 44% (95% CI, 0.28-0.60; I2 = 99.8%), 6% (95% CI, 0.02-0.09; I2 = 97.2%), and 9% (95% CI, 0.05-0.13; I2 = 97.1%), respectively. Chest injuries were diagnosed by WBCT in 39% (95% CI, 0.28-0.51; I2 = 99.8%), abdominal injuries in 23% (95% CI, 0.03-0.43; I2 = 99.9%) of cases, spinal injuries 19% (95% CI, 0.11-0.27; I2 = 99.4%), extremity injuries 33% (95% CI, 0.23-0.43; I2 = 99.2%), and pelvic injuries 11% (95% CI, 0.04-0.18; I2 = 97.4%). A mortality odd ratio of 0.94 (95% CI, 0.83-1.06; I2 = 40.1%) was calculated while comparing WBCT and non-WBCT groups. This systematic review and meta-analysis provide insight into the possible safety, efficacy, and efficiency of WBCT/pan-scan as a diagnostic tool for trauma patients with serious injuries, regardless of their hemodynamic status. In patients with serious injuries from trauma, whether or not there are indicators of hemodynamic instability, our recommended approach is to, wherever possible, perform a WBCT without stopping the hemostatic resuscitation. By using this technology, the optimal surgical strategy for these patients can be decided upon without causing any delays in their final care or greatly raising their radiation dose.

Preventing malware propagation in wireless sensor networks: Hybrid optimization algorithm for controlling

Malware transmission is a significant security issue in WSN, however, the influence of the attack and defensive processes on malware propagation is rarely taken into account in traditional malware propagation prevention methods. Advanced methods are in need to stop the propagation of malware of sensor nodes. With the formulation of representing dynamics among states, a new decision-making problem as the optimal control problem via hybrid optimization algorithm. The proposing model is termed as Butterfly Updated Bald Eagle Optimization based Prevention of Malware Propagation in Wireless Sensor Network (BUBEO-PMPWSN). In the proposed controlling system, optimal system parameters are analyzed via the BUBEO for preventing malware propagation in WSN. Particularly, the sensor node states considered are Susceptible, Infectious, Infectious and sleeping, recovered, Recovered and sleeping, and finally Dead. The system parameter tuning will be under the evaluation of fitness calculation under probability of infectious sensor node becoming recovered and the probability of infectious sensor node entering sleeping state. This optimal tuning strategy ensures the preventing of malware propagation. Finally, the performance of proposed BUBEO-PMPWSN model is evaluated and validated successfully by comparing other state-of-the-art models. The BUBEO-PMPWSN achieved 250 recovered nodes for time 500, while the HGS, BOA, HBA, COOT, and HHO scored 123, 115, 236, 172, and 180, respectively, for recovered nodes.

Dividend announcement and the value of sentiment analysis

Payout policy constitutes one of the most important corporate financial decisions since dividends are essential factors in determining a firm’s value. A dividend announcement generates a market signal which translates into changes in stock returns, impacting short-term price fluctuations and producing abnormal returns. The sample consists of 394 companies listed on the S&P500 index, from which 1574 dividend announcements and 7222 news items are derived during the years 2022–2023. News pieces are obtained from 58 specialized sources, and ChatGPT is used to automate the sentiment extracted from them. Using sentiment analysis, this paper shows the key role played by sentiments derived from financial news posted just after dividend announcements in predicting market reaction and helping investors to select optimal investment strategies. This paper contributes to the current literature, highlighting the influence that sentiments have on determining stock market returns.