Frequency Analysis Research Articles

Expanding Information for Flood Frequency Analysis Using a Weather Generator: Application in a Spanish Mediterranean Catchment

Study RegionThe proposed methodology has been applied in the Segura River basin (south-eastern Spain) whose hydrological regime has a high anthropic alteration and catastrophic floods have occurred at different times for centuries. The climate is generally semi-arid, with frequent droughts but also floods caused mainly by rainfall associated with mesoscale convective systems. Study FocusWe present a methodology that exploits all available information to obtain reliable low-frequency flood quantiles through the integration of different methods. First, a Weather Generator (WG) was implemented with the results from a regional study of annual maximum precipitation. Second, a rainfall temporal disaggregation procedure was carried out to capture the sub-daily behavior of flood generating storms. Third, a fully-distributed Hydrological Model (HM) was implemented including the role of sediments in extreme events. Finally, the estimation of flood quantiles using plotting positions was validated with systematic and non-systematic information. New Hydrological Insights for the RegionThe use of this process-based approach allows to reproduce the main hydrometeorological mechanisms associated with floods in the region studied. Accurate flood quantiles up to 200 years have been possible to obtain, which represents an important advance in the knowledge of the basin since reliable flood quantiles of only 20 years were adequately captured with the current observations. Finally, sediment yield has been proven to be an important factor for the region hydrographs’ reconstruction.

지역사회 문제 해결형 바이오헬스케어 분야 디지털 리빙랩의 활용 방안 연구

Objectives The purpose of this study was to understand the importance of the Bio-healthcare Digital Living Lab for solving community problems and to suggest policy improvement so that it can be utilized based on the speci-alized fields of university. Methods From September 1 to October 10, 2022, the survey was conducted on 150 students enrolled in bio-healthcare courses at universities in the Jeonbuk region, as well as faculty and community industrial company related Bio-healthcare department. The collected data were analyzed using the IBM SPSS Statistic ver. 22.0 stat-istical program. Frequency analysis, descriptive statistics, χ-square, independent t-test, and 1-way ANOVA were performed to analyze the data. Results The study showed satisfaction with the community living environment at 3.68 out of 5. By gender, it was higher in men(3.77±0.90) than in women(3.62±0.85), and by age, it was highest in people in their 20s(3.86±0.80), and satisfaction tended to decrease as age increased. Among local issues, ‘culture/leisure’ was recognized as the most important in terms of quality of life(28.2%) and an area in urgent need of improvement(27.6%), and the area expected to have the greatest ripple effect if improved was ‘jobs/start-up’(33.9%). In addition, there was a stat-istical difference in areas requiring urgent improvement and areas with large ripple effects depending on age and status(p<.05). They recognized that the bio-healthcare field would play an important role in resolving local is-sues(52.7%), and that local residents‘ participation was necessary in promoting it(70.4%), but the highest re-sponse was that they would consider their participation depending on the nature and direction of the project (48.8%). And, teenagers showed statistically significantly lowest scores in terms of possibility of solving local is-sues, possibility of improving quality of life, need for resident participation, and willingness to participate (p<.05). Conclusions In process of promoting a digital living lab in the bio-healthcare, an accurate preliminary analysis of the needs of local community residents regarding its nature and direction is necessary. And, in promoting a digital living lab that solves community problems, universities must play a role in building a digital living lab infrastructure specialized in the bio-healthcare field while experimenting with technology, products, and services through com-munity linkage. Lastly, for the expansion and sustainability of community bio-healthcare living labs, it is necessary to plan a living lab platform that considers both the community's needs and the university's specialized fields, and it is need to develop into an infrastructure rather than a project type.

Electromyography as a tool to motion analysis for people with Amyotrophic Lateral Sclerosis: A protocol for a systematic review.

Biomechanical analysis of human movement plays an essential role in understanding functional changes in people with Amyotrophic Lateral Sclerosis (ALS), providing information on muscle impairment. Studies suggest that surface electromyography (sEMG) may be able to quantify muscle activity, identify levels of fatigue, assess muscle strength, and monitor variation in limb movement. In this article, a systematic review protocol will analyze the psychometric properties of the sEMG regarding the clinical data on the skeletal muscles of people with ALS. This protocol uses the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) methodological tool. A specific field structure was defined to reach each phase. Nine scientific databases (PubMed, Web of Science, Embase, Elsevier, IEEE, Google Scholar, SciELO, PEDro, LILACS E CENTRAL) were searched. The framework developed will extract data (i.e. study information, sample information, sEMG information, intervention, and outcomes) from the selected studies using a rigorous approach. The data will be described quantitatively using frequency and trend analysis methods, and heterogeneity between the included studies will be assessed using the I2 test. The risk of bias will be summarized using the most recent prediction model risk of bias assessment tool. Be sure to include relevant statistics here, such as sample sizes, response rates, P values or Confidence Intervals. Be specific (by stating the value) rather than general (eg, "there were differences between the groups"). This protocol will map out the construction of a systematic review that will identify and synthesize the advances in movement analysis of people with ALS through sEMG, using data extracted from articles.

Detecting spatial and spatio-temporal clusters of rape in India, 2011–2020

The study aims to identify the spatial and spatio-temporal patterns of rape in India from 2011 to 2020 using crime data aggregated at the district level. The study also tries to understand persistent patterns in the spatial variation of rape incidence across the country during the study period. The annual rape data from 2011 to 2020 were extracted from the National Crime Records Bureau. Retrospective spatial and temporal cluster analyses were performed using the purely spatial (Kulldorff’s and Mann–Whitney scan statistic) and space–time scan statistic (Kulldorff’s based on the discrete Poisson model). Cluster frequency analysis was performed. Results showed the spatial heterogeneity in the pattern of rape crime across the country as well as its localization among geographically contiguous regions across time and space. The detected primary spatial clusters (P < 0.05) persisted mainly in the Central, North, and North Eastern zones of the country over the ten year study period. The primary spatio-temporal cluster (LLR = 5560.09, P < 0.001) appeared between the time frame 2014 to 2016 and was concentrated mainly in the Northern zone. Thirty-seven districts of India (5.78%) contributed to spatial clusters in all years of the study period. The heterogeneous distribution of rape across India could be due to the spatio-temporal variations in the determinants of rape (such as socioeconomic status, demographics, urbanisation, and gender equality) across the country. Identification of the localized rape clusters could result in understanding the contextual factors of rape and, thereby be beneficial to national and regional rape control strategies.

Digital detection of play characters’ relationships in Shakespeare’s plays: extended cross-correlation analysis of the character appearance frequencies

Digital detection of play characters’ relationships in Shakespeare’s plays: extended cross-correlation analysis of the character appearance frequencies

Peak frequency mapping characteristics in patients with scar-related atypical atrial reentrant tachycardias; findings from a novel automated annotation algorithm to detect near field signals

Abstract Background Atypical atrial tachycardias are commonly encountered rhythm disorders especially in patients with atrial low-voltage areas mainly due to previous catheter ablations or surgery. The peak frequency (PF) analysis of bipolar EGMs is a novel automated annotation tool which is mainly based on differentiation of near field signals from far field signals. Purpose In this study, we aimed to evaluate the association between PF analysis of voltage maps in low-voltage zones with the critical isthmus and termination sites of ATs. Methods In this retrospective analysis, we included a total of 36 patients (7 with right AT, 25 left AT, 4 biatrial). Omnipolar maps of RA and LA were created during AT using Ensite X Mapping system and HD-Grid catheter. Normal voltage is defined as ≥ 0.5 mV, borderline 0.1-0.5 mV and scar &amp;lt;0.1 mV. Only patients with acute termination of tachycardia with RF ablation were included. The sites within the 10 mm radius from the tachycardia termination site with RF were analysed in terms of voltage characteristics and PF analysis. Results The mean age of the study population was 53±15. Among 36 patients a total of 46 activation maps were created and 44 reentrant ATs were mapped. (24 (54.6%) ATs were macroreentry, 17 (38.6%) ATs were localized reentry and 3 ATs (6.8%) were dual-loop reentry). The low-voltage (LV) zones comprised 31.5±20.6% and 24.5±12.6% of total LA and RA, respectively. All AT termination sites using radiofrequency energy were located within the LV zones having high frequency activity using 250 Hz as the cut-off. The sensitivity of LV-NF zones to predict termination sites of re-entry was 97.2%. Conclusion The PF analysis of atrial substrate in the vicinity of the termination site of re-entrant ATs demonstrated high frequency signals within the low voltage zones. Therefore, addition of PF analysis with emphasis over voltage mapping may refine critical sites of reentry in LV regions.

Precordial activation sequences from low frequency analysis in left bundle branch block patients: left bundle branch area pacing vs right ventricular pacing

Abstract Introduction Left bundle branch area pacing (LBBAP) provides a more synchronous and physiological ventricular activation than conventional right ventricular pacing (RVP) in LBBB patients. QRS duration (QRSd) is the standard measurement for assessing depolarization synchrony, but it only provides information about the activation time and not about the activation sequence. Purpose Our aim is to assess the activation sequence by precordial activation delay (pAD) using a low-frequency (LF) ECG method comparing baseline and paced ECG in LBBAP and RVP patients. Methods Twelve-lead ECGs recordings were acquired from 29 patients with LBBB (16 LBBAP and 13 RVP) after 24 hours of sequential LBBAP or RVP. LF-ECG was employed for QRS-complex analysis. The activation time for each lead was computed and an activation sequence constructed by linking them. pAD was calculated as the time between the first and the last lead activation. pAD provides information about both, the delay in ventricular depolarization as indicated by its magnitude, and the depolarization direction (as it can take a positive or negative value indicating a left or right ventricle delay, respectively). Results At baseline, both groups (LBBAP and RVP) showed the latest activation at V5-V6, supported by positive median pAD values with no statistically significant differences between both groups (50 (21, 65) vs. 54 (17, 67) ms, p=0.93). LBBAP reduced V6 delay and pAD values compared to the baseline QRS (basal: 50 (21, 65) vs. paced: 2 (-18, 25) ms, p&amp;lt;0.001) while RVP did not exhibit any difference (basal: 54 (17, 67) vs. paced: 36 (19, 53) ms, p=0.33). LBBAP provided lower pAD values when compared to RVP (2 (-18, 25) vs. 36 (19, 53) ms, p&amp;lt;0.01). Conclusions pAD measured using a LF-ECG analysis is a feasible method to evaluate depolarization synchrony and provides complementary information to QRSd. In contrast to RVP, LBBAP generates a physiological ventricular activation sequence in patients with LBBB.Baseline patients characteristicsVentricular activation sequences and pAD

Secular structure of 1:2 and 1:3 mean motion resonances with Neptune

The 1:N mean motion resonances (MMRs) with Neptune are of particular interest in astrophysical research because they have two asymmetric resonance islands, where the distribution of trapped objects may bear important clues to resolving the history of the Solar System. To explore the dynamics of these resonances and to investigate whether the imprints left by the early stage evolution can be preserved in the resonances, we conducted a comprehensive analysis of the 1:2 and 1:3 resonances. By mainly adopting the frequency analysis method, we calculated the proper frequencies of the motion of objects in the resonances and determined the secular mechanisms that influence the dynamics. Using the spectral number (SN) as an indicator of orbital regularity, we constructed dynamical maps on representative planes. After comparing the structures in the maps with the locations of the secular mechanisms, we find that the von-Zeipel-Lidov-Kozai mechanism and the $g=2s$ mechanism destabilize the influenced orbits and thus sculpt the overall structure of the 1:2 and 1:3 resonances. The secular resonance of $2g-s=s_8$ opens a channel for objects to switch between the leading and trailing resonance islands, which can alter the population ratio between these two islands. The secondary resonances associated with the quasi 2:1 resonance between Uranus and Neptune were also detected, likely introducing more chaos to the motion. The fine dynamical structures of the 1:2 and 1:3 resonances revealed in this paper, combined with knowledge of resonant capture, provide a compelling explanation for the eccentricity distribution of observed Twotinos. Furthermore, we anticipate a more complete understanding of the history of planetary migration in the Solar System can be achieved by comparing the results in this paper with the populations in the 1:N resonances, with forthcoming observations offering more objects for study in the future.

Theoretical study of a series of 1,2-diazete based trinitromethyl derivatives as potential energetic compounds.

Explosive properties of novel potential high energy density materials of a series of 1,2-diazete-based molecules with trinitromethyl functional group were investigated computationally. All the sixty seven molecules were optimised to obtain their molecular geometries and electronic structures. Electrostatic potential analysis was also carried out in the determination of different parameters. The calculations indicate that the majority of the compounds have high positive heat of formations, high density and good detonation performance greater than that of traditional energetic materials like RDX and HMX. They are also having comparable values of impact sensitivity. These features promise their potential to be used as energetic materials for future applications. Most of the designed molecules are having high positive oxygen balance values so that the study of these molecules can also be extended as potential candidates for oxidisers in solid propellants. Optimisation and vibrational frequency analysis of the studied molecules were done with density functional theory using B3LYP/aug-cc-pVDZ as the basis set to zero imaginary frequencies using Gaussian 09. Electrostatic potential analysis were carried using the Multiwfn program.

Effect of chalcogen atoms on the electronic band gaps of the quinoxaline containing donor-acceptor-donor type semiconducting polymers: a systematic DFT investigation.

Due to the widely known positive contributions of the quinoxaline group in organic semiconductors, we conducted a fully computational study using quantum mechanical methods to investigate the effect of quinoxaline in the electron acceptor unit with the combination of different chalcogen atoms on the band gap of a series of donor-acceptor-donor type conjugated polymers. Using density functional theory, we mainly calculated the electronic band gap values of the structures containing four different chalcogen atoms (O, S, Se, and Te) in the electron donor and acceptor units. While chalcogendiazoloquinoxaline groups were used as the electron acceptor units, furan, thiophene, selenophene, and tellurophene were used as the donor units. Our theoretical results showed that the use of heavy chalcogen atoms in both donor and acceptor units resulted in a low band gap. Besides this, the effect of heavy chalcogen atoms used in the electron donor units is much more pronounced compared to the ones used in the acceptor units. More importantly, our findings proved that the inclusion of the chalcogendiazoloquinoxaline group instead of benzochalcogenadiazole as the acceptor unit significantly decreases the electronic band gap of the conjugated polymer. The lowest band gap was found to be 0.10eV for the 4,9-di(tellurophen-2-yl)-[1,2,5]telluradiazolo[3,4-g]quinoxaline polymer. Conformational analysis of the monomers and their corresponding oligomers was performed at the B3LYP/LANL2DZ level of theory. Then, long-range corrected hybrid functional LC-BLYP in a combination with the LANL2DZ basis set was utilized for the calculation of electronic properties and HOMO and LUMO energy gaps of monomers and oligomers through the reoptimization of the lowest energy conformers obtained from the B3LYP/LANL2DZ calculations in the previous step. All energy minimum structures were confirmed through vibrational frequency analysis at both calculation levels. The Gaussian 09 rev. D.01 software was used for all calculations, and GaussView 5.0.9 for visualizations.

A resonance frequency analysis to investigate the impact of implant size on primary and secondary stability

A resonance frequency analysis to investigate the impact of implant size on primary and secondary stability

Urban flash floods modeling in Mzuzu City, Malawi based on Sentinel and MODIS data

Floods are major hazard in Mzuzu City, Malawi. This study applied geospatial and hydrological modeling techniques to map flood incidences and hazard in the city. Multi-sensor [Sentinel 1, Sentinel 2, and Moderate Resolution Imaging Spectroradiometer (MODIS)] Normalized Difference Vegetation Index (NDVI) datasets were used to determine the spatio-temporal variation of flood inundation. Ground control points collected using a participatory GIS mapping approach were used to validate the identified flood hazard areas. A Binary Logistic Regression (BLR) model was used to determine and predict the spatial variation of flood hazard as a function of selected environmental factors. The Hydrologic Engineering Center's Hydrologic Modeling System (HEC-HMS) was used to quantify the peak flow and runoff contribution needed for flood in the city. The runoff and peak flow from the HEC-HMS model were subjected to extreme value frequency analysis using the Gumbel Distribution approach before input into the Hydrologic Engineering Center River Analysis System (RAS) (HEC-RAS). The HEC-RAS model was then applied to map flood inundated areas producing flood extents maps for 100, 50, 20, and 10-year return periods, with rain-gauge and Climate Prediction Center MORPHed precipitation (CMORPH) satellite-based rainfall inputs. Results revealed that selected MODIS and Sentinel datasets were effective in delineating the spatial distribution of flood events. Distance from the river network and urban drainage are the most significant factors (p &amp;lt; 0.05) influencing flooding. Consequently, a relatively higher flood hazard probability and/susceptibility was noted in the south-eastern and western-most regions of the study area. The HEC-HMS model calibration (validation) showed satisfactory performance metrics of 0.7 (0.6) and similarly, the HEC-RAS model significantly performed satisfactorily as well (p &amp;lt; 0.05). We conclude that bias corrected satellite rainfall estimates and hydrological modeling tools can be used for flood inundation simulation especially in areas with scarce or poorly designed rain gauges such as Mzuzu City as well as those affected by climate change. These findings have important implications in informing and/updating designs of flood early warning systems and impacts mitigation plans and strategies in developing cities such as Mzuzu.

THÌ and LÀ Constructions in Vietnamese: A Study on Argument Structures

This study aims to shed light on the argument structure of the Vietnamese particles THÌ and LÀ, which function as markers of focused constituents and topic-comment structures, respectively. The research objectives are to identify the syntactic and semantic properties of constructions involving THÌ and LÀ, and to analyze their argument structures within the theoretical frameworks of construction grammar. Specifically, the constructional approach (Goldberg 1995, 2006) and radical construction grammar (Croft 2001) will be employed. The methodology involves collecting a corpus of naturally occurring data from various written sources. The data will undergo qualitative analysis to identify argument structure patterns associated with THÌ and LÀ constructions, as well as quantitative analysis of frequency and distribution. The expected findings will provide insights into the argument structures of these Vietnamese constructions, elucidating how focused constituents and topic-comment structures are marked. The study will evaluate the applicability of the chosen theoretical frameworks in accounting for the observed patterns. The findings have potential applications in natural language processing tasks requiring accurate recognition and interpretation of focused constituents and topic-comment structures, such as information extraction, machine translation, and language generation. Furthermore, the study may inform language teaching and acquisition by shedding light on the usage patterns of THÌ and LÀ in Vietnamese. The analysis is expected to contribute to a deeper understanding of argument structures in Vietnamese and potentially motivate extensions or modifications to the theoretical frameworks.

Peak frequency analysis and differentiation of near-field from far-field electrograms of the ventricular tachycardia circuit leads to successful ablation of the arrhythmia.

Peak frequency analysis and differentiation of near-field from far-field electrograms of the ventricular tachycardia circuit leads to successful ablation of the arrhythmia.

Potential of computer‐mediated communications in directing communication repair, co‐regulation patterns and student engagement

AbstractBackground studyAlthough the number of computer‐based instruction has increased drastically, the understanding of how design features of learning modality can affect learning remains incompelte. This partly stems from studies' heavy focus on modified output. Therefore, how interactive nature of computer‐mediated learning feeds into learning is under examined.ObjectivesThis study examined the potentials of multimodal and text‐based computer‐mediated communication (CMC) to support learner communication repair, co‐regulation patterns and engagement dimensions.MethodTo this end, collaborative online writing performance of 30 English as a Foreign Language learners in Moodle and online writing forum was analysed via conversation analysis. Data from stored conversation of Moodle and chat logs of writing forum were coded for communication repair to trace language related episodes (LREs), co‐regulation patterns and students' engagement dimensions.ResultsThe frequency analysis of coded data on LREs indicated while multimodal CMC involved students in global and organisational and content LREs, text‐based computer‐mediate communication involved students in morphosyntactic and lexical LREs. Results also indicated significant differences in co‐regulation patterns in multimodal and text‐based computer‐mediated communication. While students enacted planning, monitoring co‐regulation practices in multimodal computer‐mediated communication, students in text‐based CMC executed evaluation and elaboration co‐regulation practices. Findings also indicated that students were differentially engaged in learning. Students were more emotionally and socially engaged in multimodal CMC and cognitively and behaviourally engaged in text‐based computer‐mediated writing.ConclusionsThe results posit dual function for CMCs, as a mean for communication and cognitive co‐regulation. However, dynamics of interaction is influenced by the mode of interaction.

Playing without goalkeeper: the use of an empty goal in high-performance men’s handball

ABSTRACT The study aimed to 1) assess the risk of conceding a goal in an empty net; 2) characterise the context when using the empty goal (EG) rule (4:1) in handball and 3) identify the performance variables that influence the EG attacks’ efficacy. A total of 974 EG attacks were sampled from 65 matches of the 2022 European Men’s Handball Championship. An observational tool was developed to analyse all EG attacks. Frequency analysis and the chi-square test have been performed to analyse the use of EG according to the match context. The binomial logistic regression was used to identify the variables that influence the EG attacks’ effectiveness. The results demonstrated that the goalkeeper was replaced mainly to maintain numerical equality. To create offensive superiority, the teams mostly used EG during the last quarter of the match playing under a small score disadvantage. The risk of conceding a goal in the empty net was higher if a team failed to score in previous possession. No relationship was found between the team’s final classification and the frequency of EG use, nor the efficacy of EG situations. Two variables have been identified as significant for the 6 × 6 + GK possession outcome: 2nd pivot position and shot zone.

An observational cross-sectional study of the role of magnetic resonance imaging in the evaluation of T2-weighted hyperintensities in the spinal cord in tertiary care hospital in central India

Background T2-weighted hyperintensities in the spinal cord are a complex and diagnostically challenging entity that can present with diverse clinical features. This study protocol outlines a comprehensive investigation to understand the causes, clinical and imaging characteristics, and correlation with pathological findings of T2-weighted hyperintensities in the spinal cord. By establishing a systematic assessment approach, this study seeks to provide valuable insights into these abnormalities’ diagnostic and prognostic implications. Methods The study will be conducted as a prospective observational design. Patients with clinically diagnosed or suspected spinal cord injury presenting with intramedullary T2-weighted hyperintensity and referred for MRI evaluation will be included. Data collection will encompass patient demographics, clinical features, and extensive imaging parameters. Pathological data, when available, will be correlated with imaging findings. Various statistical methods will be employed to analyse the data, including frequency analysis, comparative tests, logistic regression, and survival analysis. Expected Results The study anticipates elucidating the spectrum of etiologies underlying T2-weighted hyperintensities in the spinal cord and their clinical and imaging profiles. The systematic approach will offer a structured diagnostic method, while correlations with pathological data will provide an enhanced understanding of these conditions. The results are expected to provide clinicians with valuable insights into diagnosing, treating, and prognosticating patients with spinal cord hyperintensities.

Lexical Expressions of Motion in Physical Environments a Cognitive Linguistics Perspective

This study aims to delve into the interaction between motion verbs, manners, and paths in the Vietnamese language to look at the lexicalization of motion occurrences. Utilizing Talmy's lexicalization patterns for cognitive linguistics, the study seeks to understand how Vietnamese encodes and conceptualizes motion events in a variety of physical contexts, such as the air, water, and land. A mixed-methods approach is used in this work, integrating qualitative analysis of annotated textual data with quantitative frequency analysis. Vietnamese has a rich system of motion verbs that may be paired with manner and path expressions to produce complex and subtle descriptions of movement, according to the research. The language displays intricate differences when describing the direction, velocity, and kind of vehicle of motion, in addition to various linear, curved, vertical, circular, and multidirectional routes. The complex interplay between language, cognition, and the embodied experience of motion is highlighted by this linguistic variety, which is a reflection of Vietnamese speakers' astute observation and interpretation of the physical world. The work adds to our knowledge of how language organizes and expresses the basic idea of motion and provides insights into the cognitive and cultural bases of language expression.

When algebra makes you smile: Playful engagement with early algebraic practices

BackgroundThe typical competitive and results-driven approach to school mathematics has traditionally been conceived as devoid of play, joy, and positive affect. AimsIn this paper we address the following questions: What markers of positive affect are observed while students are doing early algebra? Specifically, how are students’ markers of joy related to early algebraic practices? What are the characteristics of playful stances to learning early algebra that are observed when children express positive epistemic affect? SampleWe analyze three cases in which elementary school students engaged in tasks from an early algebra classroom teaching experiment. MethodsDrawing from two theoretical frameworks, epistemic affect and early algebra, we conducted microgenetic analyses of lesson transcripts to identify markers of joy and early algebraic practices. We conducted frequency analyses to determine their co-occurrence. ResultsOur results indicate that children expressed joy while engaging in early algebraic practices, evidence of positive epistemic affect. We describe the aspects of each of the cases we present in terms of prior literature on playful stances to learning to further bolster our claims about the relationship between joy and engagement with the early algebraic practices. ConclusionsWe conclude that mathematical learning environments should include open opportunities for students to engage with mathematical content, with multiple entry points and ways to respond. We also conclude that early algebraic practices provide opportunities for playfully engagement and positive epistemic affect.

Estimating rainfall-runoff parameters for ungauged catchments: a case study in Turkiye

ABSTRACT Determining water yield and flood discharges in catchments is a vital aspect of hydrology. This entails considering precipitation and runoff as key hydrological parameters. Constructing infrastructure like hydroelectric plants and regulators over streams necessitates continuous, accurate flow, and meteorological observations spanning at least 25 years. However, in developing nations, economic factors often impede such observations. This study proposes a method to estimate peak rainfall and flow values for ungauged basins with varying return periods by utilizing from gauged basins and spatial variables. Flood calculations were carried out for the ungauged Rabat River basin. In this study, regional flood frequency analysis was carried out using the flow values of the flow gauging stations neighboring the basin. In addition, maximum flow values were calculated using Moscus and the DSI synthetic method. Two- and three-parameter distributions were used to estimate 50-, 100-, 200- and 500-year flood return values at stations with observation periods ranging from 15 to 64 years. Kolmogorov–Smirnov and Probability Line Correlation coefficient (Chi-square) tests were applied to check the suitability of these distributions and the most appropriate distributions were found. This yielded an estimation for the flow values of the Rabat River, indicating the method's reliability for forecasting runoff-rainfall in the ungauged basin.