Abstract The influence of occupant behaviour in buildings is widely discussed as one of the causes for the gap between energy use estimated via computer simulation and during building operation. Knowing the main drivers for adjustments in building systems is essential to guide the development of mathematical models for such behaviours. The aim of this study is to evaluate the main motivating agents for adjusting windows, luminaires, and air-conditioning in offices. Two offices were monitored using sensors that collected data from the internal environment and user interaction with such systems. Rainfall and external and internal air temperatures were considered influential for the interaction with window systems. The increase in internal and external temperatures had even more influence on interactions with air-conditioners. The main conclusions were: there is influence of the layout of the offices in the sharing and control of windows and efficiency of passive strategies, such as the use of natural and cross ventilation; and there is an influence of the increase in internal temperature compared to external temperature in the predictability of opening windows and turning air-conditioning devices on. operation behaviours luminaires airconditioning conditioning airconditioners. airconditioners conditioners. conditioners air-conditioners strategies ventilation

Resumo Ainfluência do comportamento dos usuários em edificações é amplamente discutida como uma das causas para discrepâncias entre consumos energéticos esperados, durante a fase de projeto, e consumos durante a operação. Conhecer os principais motivadores para ajustes nos sistemas de edificações é imprescindível para aprimorar a modelagem desses comportamentos. O objetivo deste estudo é avaliar os principais agentes motivadores para o ajuste das janelas, luminárias e aparelhos de ar-condicionado em escritórios. Dois escritórios foram monitorados por meio de sensores que coletaram dados de qualidade do ambiente interno e comportamento de usuário. Foram consideradas influentes para a interação com sistemas de janelas a pluviometria e as temperaturas do ar externo e interno. O aumento das temperaturas interna e externa apresentou ainda mais influência na interaçãocom aparelhos de ar-condicionado. Duas foram as principais conclusões: há influência do layout dos escritórios no compartilhamento e controle das janelas e eficiência de estratégias passivas, como o uso de ventilação natural e cruzada; e há influência do aumento da temperatura interna em comparação à externa na previsibilidade de abertura de janelas e acionamento de aparelhos de ar-condicionado. esperados projeto operação comportamentos arcondicionado condicionado usuário arcondicionado. condicionado. conclusões passivas cruzada

Summary: A methodology is proposed for the interpretation of gas emissions that come from the soil based on the integration of the primary actors in the production systems and members of the ecosystems. The methodology presents data in units that are easy to understand by people outside the study of gas emissions in different ecosystems and production systems, and optimizes the calculation of small and medium scale predictions through estimation with a high degree of ratio and mathematical adjustment. From the use of the ideal gas equation, it was possible to develop the methodology to obtain a conversion factor taking into account variables such as the pressure and temperature of the site where the gas quantification experiment is being carried out. With the aforementioned, it is easier to obtain the constant of the molar volume of the container used and data transformation to ensure compliance with basic statistical parameters such as normality, variance similar to zero, and confidence intervals with less deviation. The present methodological development represents a tool for the generation of data at the laboratory and plot level with mathematical support that facilitates the execution of mathematical models in comparison with other methodologies.

Resumen: Se propone una metodología para la interpretación de las emisiones de gases que proceden del suelo a partir de la integración de los actores primarios en los sistemas de producción e integrantes de los ecosistemas. La metodología presenta datos en unidades de fácil comprensión por personas ajenas al estudio de emisiones de gases en los distintos ecosistemas y sistemas de producción, optimiza el cálculo de predicciones a pequeña y mediana escala mediante la estimación con alto grado de razón y ajuste matemático. A partir del empleo de la ecuación general de los gases ideales se pudo desarrollar la metodología para obtener un factor de conversión teniendo en cuenta variables como la presión y temperatura del sitio donde se esté ejecutando el experimento de cuantificación de gases, con lo anterior se facilita la obtención de la constante del volumen molar propio del contenedor utilizado y la transformación de datos para garantizar el cumplimiento de parámetros estadísticos básicos como normalidad, varianza similar a cero e intervalos de confianza con menor desviación. El presente desarrollo metodológico representa una herramienta para la generación de datos a nivel de laboratorio y parcelario con soporte matemático que facilita la ejecución de modelos matemáticos en comparación con otras metodologías.

Abstract: This paper aims to present the elements to be considered for the argumentative practices of high school mathematics teachers in Costa Rica in 2023. The paper explains and demonstrates the different notions of argumentation and their differences. Costa Rica, like many OECD countries, faces the challenge of educating competent citizens in different areas of knowledge, including mathematics, who in turn must develop the ability to argue. However, the results obtained by the country in the most recent assessment of the PISA tests (2018) were not good. The article reviews a pilot experience conducted with practicing teachers, graduates of different universities and working in different institutions, on their beliefs about argumentation. Finally, the article reviews the reasons why the country’s public universities should promote the use of argumentation from the beginning of teacher training. The main conclusion highlights the need to train professionals who are able to argue through experiences and models that develop a pedagogical mediation of argumentation in their teaching work.

Resumo: O objetivo deste escrito é apresentar elementos a considerar nas práticas argumentativas dos docentes de matemática do ensino secundário na Costa Rica em 2023. São abordadas as diferentes noções de argumentação e suas diferenças com a explicação e a demonstração. A Costa Rica, como muitos países perten- centes à OCDE, enfrenta o desafio de formar cidadãos competentes em diferentes áreas do saber; uma delas é a matemática e dentro desta deve ser desenvolvida a competência de argumentação, entre outras. Contudo, os resultados alcançados pelo país na sua última avaliação nos testes PISA (2018) não são bons e possuem múltiplos fatores que se vinculam neste ensaio com dados de uma experiência piloto com docentes em exercício, graduados de diferentes universidades e que trabalham em diferentes instituições, sobre suas crenças sobre a argumentação. Por fim, é revisada a importância de fomentar a argumentação desde a formação inicial de do- centes nas universidades públicas do país. A principal conclusão encontrada destaca a necessidade de formar profissionais com noção ampla de argumentação, com experiências e modelos que lhes permitam desenvolver uma mediação pedagógica desta competência no seu trabalho docente.

Resumen: El objetivo de este escrito es presentar elementos por considerar en las prácticas argumentativas de docentes de Matemáticas de la enseñanza secundaria de Costa Rica en el 2023. Se abordan las diferentes nociones de argumentación y sus diferencias con explicar y demostrar. Costa Rica, al igual que muchos países pertenecientes a la OCDE, se enfrenta al reto de formar personas ciudadanas competentes en diferentes áreas del saber; una de ellas es la Matemática y dentro de esta se debe desarrollar la competencia de argumentar, entre otras. Sin embargo, los resultados alcanzados por el país en su última evaluación en las pruebas PISA (2018) no son buenos y tienen múltiples factores que se vinculan en el presente ensayo con datos de una experiencia piloto con docentes en ejercicio, graduados de diferentes universidades y que laboran en distintas instituciones, sobre sus creencias acerca de la argumentación. Finalmente, se revisa la importancia de fomentar la argumentación desde la formación inicial de docentes en las universidades públicas del país. La principal conclusión hallada destaca la necesidad de formar profesionales con una noción amplia de argumentación, con experiencias y modelos que le permitan desarrollar una mediación pedagógica de esta competencia en su labor docente.

ABSTRACT The drying process is paramount for maintaining seed quality, where the temperature during this process directly influences germination and vigor, especially for vegetable species harvested with high moisture content. This research aimed to determine and model the drying curves of S. aethiopicum (cultivar Tinguá-verde-claro) seeds at temperatures of 35, 38, 41, and 44 ºC, as well as to evaluate the physiological quality of the seeds after drying. A completely randomized design was used, with four drying temperatures (35, 38, 41, and 44 ºC) and four replicates. Nine mathematical models were fitted using the non-linear regression analysis by the Gauss-Newton method, and the goodness of fit was assessed based on the magnitude of the coefficient of determination (R2), chi-square test (χ2), relative mean error (P), and estimated mean error (SE). Seed quality was evaluated by germination test (G), electrical conductivity (EC), and accelerated aging (AA). The Modified Midilli model best represents the drying curves of S. aethiopicum seeds at the studied temperatures. Seeds with higher germination and vigor, meaning lower electrical conductivity values and higher germination rates after accelerated aging, are achieved through drying at 35 and 38 ºC. vigor content S cultivar Tinguáverdeclaro Tinguá verde claro Tinguá-verde-claro 41 4 ºC used (35 replicates nonlinear non linear GaussNewton Gauss Newton method R2, R2 R , (R2) chisquare chi square χ2, χ2 χ (χ2) P, P (P) SE. SE . (SE) G, G (G) EC, EC (EC) AA. AA (AA) 3 (3 (R2 (χ2 (P (SE (G (EC (AA ( (R (χ

RESUMO O processo de secagem é de suma importância para a manutenção da qualidade das sementes, onde a temperatura de condução deste processo exerce influência direta sobre a germinação e vigor, sobretudo para as espécies olerícolas que são colhidas com alto teor de água. O objetivo desta pesquisa foi determinar e modelar as curvas de secagem de sementes de jiló (cultivar Tinguá-verde-claro) nas temperaturas de 35, 38, 41 e 44 ºC, bem como avaliar a qualidade fisiológica das sementes após a secagem. Foi utilizado o delineamento inteiramente casualizado, sendo quatro temperaturas de secagem (35, 38, 41 e 44 ºC) com quatro repetições. Nove modelos matemáticos foram ajustados por meio de análise de regressão não linear pelo método de Gauss-Newton, e o grau de ajuste foi avaliado com base na magnitude do coeficiente de determinação (R2), teste qui-quadrado (χ2), erro médio relativo (P) e erro médio estimado (SE). A qualidade das sementes foi avaliada pelo teste de germinação (G), condutividade elétrica (CE) e envelhecimento acelerado (EA). O modelo ‘Midilli Modificado’ é o que melhor representa as curvas de secagem das sementes de jiló nas temperaturas estudadas. Sementes com maior germinação e vigor, ou seja, com menores valores de CE e maiores taxas de germinação após EA, são alcançadas através da secagem a 35 e 38 ºC. vigor água cultivar Tinguáverdeclaro Tinguá verde claro Tinguá-verde-claro 4 ºC casualizado (35 repetições GaussNewton, GaussNewton Gauss Newton, Newton Gauss-Newton R2, R2 R , (R2) quiquadrado qui quadrado χ2, χ2 χ (χ2) P (P SE. SE . (SE) G, G (G) (CE EA. EA (EA) Midilli Modificado estudadas seja 3 (3 (R2 (χ2 (SE (G (EA ( (R (χ

Abstract: This research proposes two models for the problem of short-term economic dispatch of electrical power systems through nonlinear programming (NLP). The problems raised will be resolved through the cost function of the classic economic dispatch where thermal and hydraulic generation plants will be considered to obtain the electrical power generated in each of the nodes. The proposed methodology will be used for a short-term period of 24 hours with different hourly demand, as it is a short-term dispatch, it focuses on the delivery of power that covers the designated demand in each schedule, so it will not consider a deficit cost or uncertainty in the variables in any of the cases. In the first instance, the model will be developed for a single node with cascade reservoirs, while the second case will be developed in the IEEE 14-bus system. The non-linear programming shows satisfactory results, complying with the operational restrictions implemented in the mathematical model, in addition, the participation of thermal generation is considerably reduced, which represents a lower cost. The first model of a node is validated through bibliography, obtaining an operating cost of $904,990. In the same way, complying with all the designated parameters, the second model obtains a total cost of $129,800, satisfying the total demand in both cases, subject to each of its restrictions.

Resumen: La presente investigación propone dos modelos al problema de despacho económico a corto plazo de los sistemas eléctricos de potencia por medio de la programación no lineal (PNL). Los problemas planteados serán resueltos mediante la función de costo del despacho económico clásico en donde se considerarán centrales de generación térmica e hidráulicas para obtención de la potencia eléctrica generada en cada uno de los nodos, la metodología propuesta será utilizada para un periodo a corto plazo de 24 horas con diferente demanda horaria, al ser un despacho a corto plazo este se enfoca en la entrega de potencia que cubra la demanda designada en cada horario, por lo que no considerará para ninguno de los casos un costo de déficit o incertidumbre en las variables. En primera instancia se desarrollará el modelo para un solo nodo con embalses en cascada, mientras que el segundo caso será desarrollado en el sistema de 14 buses de la IEEE. La programación no lineal muestra resultados satisfactorios cumpliendo con las restricciones operativas implementadas en el modelo matemático, además se reduce considerablemente la participación de generación térmica lo que representa menor costo, el primer modelo de un nodo es validado mediante bibliografía obteniendo un costo de operación de $904.990. De la misma forma, cumpliendo con todos los parámetros designados, el segundo modelo llega a obtener un costo total de $129.802,16 satisfaciendo el total de la demanda en ambos casos, sujeto a cada una de sus restricciones.

Abstracts A review of the mathematical models that predict visual quality of intraocular lenses as a function of the optical quality parameters that characterize them, and a review of the methodologies used for the simulation of vision with intraocular lenses are presented. It is shown that the existing simulation techniques could be useful to evaluate the different models of visual quality in multifocal design intraocular.

Resumen Se presenta una revisión de los modelos matemáticos que predicen calidad visual de lentes intraoculares en función de los parámetros de calidad óptica que las caracterizan, y una revisión de las metodologías empleadas para la simulación de visión con lentes intraoculares. Se muestra que las técnicas de simulación existentes podrían ser de utilidad para evaluar los distintos modelos de calidad visual en lentes intraoculares de diseño multifocal.

RESUMEN El objetivo del presente trabajo es ofrecer una estrategia didáctica que contribuya a la solución de problemas matemáticos-profesionales con enfoque formativo agroecológico por los estudiantes de Agronomía. El diagnóstico del proceso de enseñanza-aprendizaje de la Matemática, la revisión de la bibliografía básica y programas de estudio revelaron una insuficiente sistematización didáctico-metodológico en la interrelación de los contenidos de la profesión, la asignatura Matemática y lo contextual agroecológico. La aplicación de la estrategia didáctica propició el interés por el estudio de la Matemática, así como la utilización de modelos y métodos matemáticos en la solución a los problemas objeto de estudio.

ABSTRACT The objective of this work is to offer a didactic strategy that contributes to the solution of mathematical-professional problems with an agroecological formative approach by Agronomy students. The diagnosis of the teaching-learning process of Mathematics, the review of the basic bibliography and study programs revealed an insufficient didactic-methodological systematization in the interrelation of the contents of the profession, the subject Mathematics and the agroecological contextual. The application of the didactic strategy favored the interest in the study of Mathematics, as well as the use of mathematical models and methods in the solution to the problems under study.

RESUMEN Los pronósticos de las precipitaciones tienen gran importancia para prevenir desastres, pérdidas económicas en cultivos y varios aspectos importantes para la hidroeconomía del país, de ahí la necesidad de desarrollar modelos de predicción de precipitaciones. En el Centro Meteorológico Provincial de Villa Clara (CMPVC) se emplean modelos matemáticos con un nivel de precisión alto, pero requieren mucho tiempo de procesamiento. De ahí la necesidad de buscar maneras más actuales y precisas para realizar pronósticos de lluvia acertados, pero de manera más rápida. El progreso de la inteligencia artificial y en especial, las redes neuronales artificiales han permitido desarrollar modelos para dar solución al problema de predicción de precipitaciones; mediante las métricas proporcionadas por la Organización Meteorológica Mundial (OMM) comprendidas entre los años 1975 hasta el 2016. En este trabajo se realiza un análisis de los diferentes modelos de regresión con múltiples salidas para predecir las precipitaciones en los meses mayo, junio, julio y agosto. Los modelos de regresión que más se ajustaron a esta problemática fueron la regresión lineal, el árbol de regresión, el k-vecinos más cercanos, la regresión directa, la regresión encadenada y el perceptrón multicapa. Luego de realizar las corridas de los modelos resultó el perceptrón multicapa, el modelo de regresión con mejores resultados, con un alto grado de eficacia para el pronóstico de las precipitaciones.

ABSTRACT Rainfall forecasts are of great importance to prevent disasters, economic losses in crops and several important aspects for the country's hydroeconomy, hence the need to develop rainfall prediction models. At the Villa Clara Provincial Meteorological Center (CMPVC), mathematical models with a high level of accuracy are used, but they require a lot of processing time. Hence, the need to look for more current and accurate, ways to make accurate rainfall forecasts but in a faster way. The progress of artificial intelligence and especially artificial neural networks have allowed the development of models to solve the problem of rainfall prediction; using the metrics provided by the World Meteorological Organization (WMO) from 1975 to 2016. In this work, an analysis of the different regression models with multiple outputs to predict rainfall is carry out in the months of May, June, July and August. The regression models that best fit this problem were linear regression, regression tree, k-nearest neighbors, direct regression, chained regression and multilayer perceptron. After running the models, the multilayer perceptron was the regression model with the best results, with a high degree of efficiency for rainfall forecasting.

ABSTRACT In subsurface drip irrigation systems, knowledge of the three-dimensional advancement of water in the soil is essential for selecting emitter spacing and installation depth. This research aimed to develop and test different mathematical models to estimate water distribution in the soil under subsurface drip irrigation. The experiment was set up in a completely randomized design with four replicates. The experimental arrangement was of split-plot in time, with different dripper installation depths in the plots (0, 5, 10, 15, 20, 25, and 30 cm) and in the subplots irrigation application times (0, 60, 120, 180, and 240 min). Three models (SLIDE 6.0, polynomial regression, and SPSS 2.0) were constructed to estimate the water distribution in the soil profile. All models showed statistical indexes within acceptable ranges. In comparison, the model generated in the numerical software SLIDE 6.0 was the one that presented the best performance, followed by SPSS 2.0 and polynomial regression. The generated models were efficient and simple, producing good results in predicting the water distribution in the soil profile under the studied conditions. systems threedimensional three dimensional depth replicates splitplot split plot time 0, 0 (0 5 10 15 20 25 3 cm 60 120 180 24 min. min . min) 6 regression 2 ranges comparison 6. performance 2. simple conditions ( 1 12 18

RESUMO Em sistemas de irrigação por gotejamento subsuperficial, o conhecimento do avanço tridimensional da água no solo é essencial na seleção do espaçamento e profundidade de instalação dos emissores. O objetivo desta pesquisa foi desenvolver e testar diferentes modelos matemáticos para estimar a distribuição de água no solo sob irrigação por gotejamento subsuperficial. O experimento foi montado em delineamento inteiramente casualizado com quatro repetições. O arranjo experimental foi de parcelas subdivididas no tempo, tendo nas parcelas diferentes profundidades de instalação de gotejadoras (0, 5, 10, 15, 20, 25 e 30 cm) e nas subparcelas tempos de aplicação da irrigação (0, 60, 120, 180 e 240 min). Foram construídos três modelos (SLIDE 6.0, regressão polinomial e SPSS 2.0) para estimar a distribuição de água no perfil do solo. Todos os modelos apresentaram índices estatísticos dentro de faixas aceitáveis. Na comparação, o modelo gerado no software numérico SLIDE 6.0 foi o que apresentou melhor desempenho, seguido do SPSS 2.0 e regressão polinomial. Os modelos gerados foram eficientes e simples, apresentando bons resultados na predição da distribuição de água no perfil do solo para as condições estudadas. subsuperficial emissores repetições tempo 0, 0 (0 5 10 15 20 2 3 cm 60 120 18 24 min. min . min) 6 aceitáveis comparação 6. desempenho 2. simples estudadas ( 1 12

In hierdie studie word optimale prysbepaling en lotgrootte produksiebeleidsmodelle met pryssensitiewe vraag na verswakkende produkte oorweeg, met inagneming van twee afsonderlike produksietempo's. Dit is moontlik om produksie teen een tempo te begin en dan na 'n ander tempo oor te skakel na 'n tydperk. So 'n scenario is aantreklik, aangesien 'n groot aanvanklike voorraad geproduseerde goedere vermy kan word deur produksie teen 'n beskeie tempo te begin, en sodoende die aanvanklike belegging en die houkoste te verminder. Verder word die vyfde-orde vergelyking verkry wanneer die vergelyking vir optimale prysbepaling afgelei word. Maksimering van die wins word bereken op grond van 'n vyfde-orde vergelyking. Beide optimale pryse en produksielotgrootte is besluitveranderlikes, en optimale siklustyd is ook een van die besluitveranderlikes vir die bepaling van prysgelykbreekpunte. Wat inligting betref, het geen navorser optimale prysbepaling en produksielotgrootte-beleide in twee-tempo-van-produksie-modelle vir hul studie ondersoek nie. Die doel van die studie is om die optimale produksie, optimale pryse en optimale siklustyd te ondersoek om die totale koste te verminder en die totale wins te maksimeer. Beide prys-gelykbreekpunt en winsmaksimering word oorweeg. 'n Toepaslike wiskundige model word ontwikkel. 'n Illustratiewe voorbeeld word verskaf en numeries bekragtig met behulp van 'n sensitiwiteitsanalise. Microsoft Visual Basic 6.0 is gebruik om die model se uitkomsvalidering te kodeer.

In the present study, optimal pricing and optimal lot size production policy models with price-sensitive demand of deteriorating products are considered, taking into account two distinct production rates. It is possible to begin production at one rate and then switch to a different rate after a period of time. Such a scenario is appealing, in that a big initial stock of produced goods can be avoided by starting production at a modest pace, thus reducing the initial investment and the holding cost. Further, the fifth-order equation is obtained when the equation for optimal pricing is derived. Maximising the profit is calculated based on a fifth-order equation. Both optimal pricing and production lot size are decision variables, and optimal cycle time is also one of the decision variables for determining price break-even points. As far as information is concerned, no researcher has examined optimal pricing and production lot size policies in two-rates-of-production models for their study. The objective of the present study is to examine the optimal production, optimal pricing, and optimal cycle time to reduce the total cost and to maximise the total profit. Both price break-even point and profit maximisation are considered. An appropriate mathematical model is developed. An illustrative example is provided and numerically validated using a sensitivity analysis. Microsoft Visual Basic 6.0 was used to code the model's outcome validation.

RESUMEN El objetivo del presente estudio fue emplear modelos matemáticos para la predicción de los rendimientos de la madera aserrada a partir de parámetros dendrométricos de los árboles en pie, que permitan una adecuada definición de su potencial en el aserradero Combate de la Tenería. Los rendimientos de madera aserrada están influenciados por la posición de la troza en el fuste del árbol, con un decrecimiento en dependencia de la altura. Las cuatro ecuaciones construidas para determinar el rendimiento de la madera aserrada tienen aceptables coeficientes de correlación, determinación y bajos errores estándar de estimación. Sin embargo, el mejor comportamiento lo posee el modelo Ln (rend) = 1,084 + 0,464 * ln d1,30 0,1201 ln que tiene mejor ajuste, las variables independientes explican el 67 % y el menor valor del error estándar de estimación. En función del análisis de elasticidad se puede definir el diámetro a 1,30 m es la variable predictora de mayor influencia positiva sobre el incremento de los rendimientos de madera aserrada. La conicidad tiene un efecto negativo sobre el volumen y valor de la madera aserrada. Con la implementación del control estadístico del aserrado, se detectó que el proceso está fuera de control, lo cual implica la necesidad de realizar el análisis correspondiente para eliminar esta deficiencia.

RESUMO O objetivo deste estudo foi utilizar modelos matemáticos para prever o rendimento da madeira serrada com base em parâmetros dendrométricos de árvores em pé, que permitam uma definição adequada do seu potencial na serraria Combate de la Tenería. O rendimento da madeira serrada é influenciado pela posição da tora no tronco da árvore, diminuindo conforme a altura. As quatro equações construídas para determinar o rendimento da madeira serrada apresentam correlação e coeficientes de determinação aceitáveis e baixos erros padrão de estimativa. Porém, o melhor comportamento é apresentado pelo modelo Ln (rend) = 1,084 + 0,464 * ln d1,30 0,1201 ln, que apresenta o melhor ajuste, as variáveis independentes explicam 67% e o menor valor do erro padrão de estimativa. Com base na análise de elasticidade, o diâmetro pode ser definido em 1,30 m como a variável preditora com maior influência positiva no aumento do rendimento de madeira serrada. A conicidade tem um efeito negativo no volume e no valor da madeira serrada. Com a implementação do controlo estatístico da serragem, detectou-se que o processo está fora de controlo, o que implica a necessidade de realizar a análise correspondente para eliminar esta deficiência.

ABSTRACT The objective of this study was to use mathematical models for the prediction of sawnwood yields based on dendrometric parameters of standing trees, which allow an adequate definition of their potential in the Combate de la Tenería sawmill. Sawnwood yields are influenced by the position of the log in the tree trunk, with a decrease depending on the height. The four equations constructed to determine the yield of sawnwood have acceptable correlation and determination coefficients and low standard errors of estimation. However, the best behavior is shown by the model Ln (rend) = 1.084 + 0.464 * l n d 1.30 0.1201 l n which has the best fit, the independent variables explain 67% and the lowest value of the standard error of estimation. Based on the elasticity analysis, the diameter can be defined at 1.30 m, it is the predictor variable with the greatest positive influence on the increase in sawnwood yields. Taper has a negative effect on the volume and value of sawnwood. The use of the statistical control of saw detected that the process is out of control, which implies the need to carry out the corresponding analysis to eliminate this deficiency.

Abstract: The objective of this study was to evaluate the relationship between body weight (BW) and different biometric measurements in llamas (Lama glama) from the Bolivian highlands and to generate prediction models of BW. A total of 515 individual records of BW and biometric measurements were used. The measurements were taken on 202 males and 313 females aged between 0.5 and 5 years, and included: neck length (NL), withers height (WH), rump height (RH), heart girth (HG), body length (BL), abdomen circumference (AC), rib depth (RD), hip width (HW), pin bone width (PBW), thoracic width (TW), and back length (BKL). The relationships between BW and biometric measurements were developed using simple linear and multiple regression. For the evaluation, the relationship between the observed and predicted values of BW was determined by linear regression, the mean squared error of prediction (MSEP) and root MSEP (RMSEP); concordance correlation coefficient analysis was also used. The BW ranged from 22 to 122 kg. Regression equations between BW, HG and RD had an r2 of 0.94 and 0.92, respectively (RMSEP= 6.06 and 6.70 kg, respectively). The equations were highly precise (r2 >0.86) and accurate (Cb>0.98), with a reproducibility index > 0.92. The model efficiency (MEF) indicated a higher efficiency of prediction (MEF > 0.86). Using a single predictor, HG and RD accounted for more than 92% of the variation in BW. Overall, HG may be used as a single predictor to predict BW in llamas maintained under the conditions of the Bolivian highlands.

RESUMEN Introducción: La modelación de los flujos de pacientes se considera una herramienta clave para el análisis y mejora de las trayectorias intrahospitalarias. Objetivo: Desarrollar y validar, en un servicio de cirugía general, un modelo matemático para la gestión de flujos de pacientes en servicios hospitalarios. Métodos: Se desarrolló una investigación de tipo cuantitativa descriptiva. Se analizaron diferentes modelos de gestión y se identificaron brechas a solventar. Para su concepción se diseñó un procedimiento metodológico que tiene en cuenta la agrupación de pacientes en categorías diagnósticas mayores, en función de características clínicas homogéneas y similar consumo de recursos. Resultados: Se identificó como problema principal la insuficiente gestión de los flujos de pacientes. Se construyó un modelo matemático de simulación discreta que se validó mediante la comparación de datos reales del servicio y las opiniones subjetivas de especialistas. Se identificó que los recursos limitantes del sistema son las enfermeras y las camas con porcentajes de utilización de 93,377 % y 89,265 % respectivamente. Conclusiones: Se desarrolla un modelo para la gestión de los flujos de pacientes en el servicio de cirugía general y se demuestra su influencia en el análisis, el proceso de toma de decisiones y la mejora de la gestión.

ABSTRACT Introduction: Patient flow modeling is considered a key tool for the analysis and improvement of in-hospital trajectories. Objective: To develop and validate a mathematical model for the patient flows management in hospital in a General Surgery service. Methods: A descriptive quantitative research was developed. Different management models were analyzed and gaps to be solved were identified. For its conception, a methodological procedure was designed that takes into account the grouping of patients in Major Diagnostic Categories according to homogeneous clinical characteristics and similar resource consumption. Results: Insufficient patient flow management was identified as the main problem. A mathematical model of discrete simulation was built and validated by comparing real data from the service and the subjective opinions of specialists. It was identified that the limiting resources of the system are nurses and beds with utilization percentages of 93.377% and 89.265% respectively. Conclusions: A model for the patient flows management in the General Surgery service is developed and its influence on the analysis, decision-making process and management improvement is demonstrated.

Abstract. - This publication presents the development of a method that seeks to monitor the parameters β (shape) and η (scale) for each component-subsystem combination following the Weibull distribution, necessary for the calculation of the reliability of the man-machine system in the machining area. This system defines the workshops of the metal-mechanic, with high-mix and low-volume batch production where conventional and Computerized Numerical Control (CNC) machines are involved, which share the manufacturing of parts that sometimes are unique, or their manufacturing period is short. The design of the man-machine system is based on the analysis of the failures of non-conforming parts in the machining area and on the failure rates, which the statistical model is developed for its evaluation, considering the 2-parameter Weibull distribution, and a redundant system with series-parallel configuration. The results obtained were based on the theoretical-practical, using mathematical and statistical models, as well as the Study Case. With the use of mathematical and statistical models, it is demonstrated that the probability of failure (risk) of the man-machine system is time-dependent and is generated by mechanical type stresses, which occur in the manufacture of parts.

Resumen. - Esta publicación presenta el desarrollo de un método que busca monitorear los parámetros β (forma) y η (escala) para cada combinación componente-subsistema siguiendo la distribución de Weibull, necesarios para el cálculo de la confiabilidad del sistema hombre-máquina en el área de maquinado. Este sistema define los talleres de la metalmecánica, con producción por lotes de alta mezcla y bajo volumen donde intervienen máquinas convencionales y de Control Numérico Computarizado (CNC), que comparten la fabricación de piezas que en ocasiones son únicas, o su periodo de fabricación es corto. El diseño del sistema hombre-máquina se basa en el análisis de los fallos de piezas no conformes en el área de mecanizado y en las tasas de fallo, para cuya evaluación se desarrolla el modelo estadístico, considerando la distribución de Weibull de 2 parámetros, y un sistema redundante con configuración serie-paralelo. Los resultados obtenidos se basaron en el teórico-práctico, utilizando modelos matemáticos y estadísticos, así como el Caso de Estudio. Con el uso de modelos matemáticos y estadísticos, se demuestra que la probabilidad de falla (riesgo) del sistema hombre-máquina depende del tiempo y es generada por tensiones de tipo mecánico, que ocurren en la fabricación de las piezas.

ABSTRACT The study was carried out at the Tío Pedro farm in the municipality of Venezuela, in the province of Ciego de Ávila, with the objective of proposing mathematical models to estimate the hydraulic parameters of a pumping system using the furrow irrigation technique for the cultivation of black bean. The results showed expected fluctuations in hydraulic parameters such as flow rate, head, hydraulic power, pumping time, and pumped volume. Functional relationships were found between flow and pumping head, as well as between hydraulic power, flow and pumping head. These ratios can improve pump system performance, save energy, and increase pump efficiency. In addition, functions were developed to predict the characteristic curves of the load, the efficiency of the pump and the system in general. These results can improve energy efficiency and water management in agriculture.

RESUMEN El estudio se realizó en la finca Tío Pedro en el municipio de Venezuela, en la provincia de Ciego de Ávila, tuvo como objetivo proponer modelos matemáticos para estimar los parámetros hidráulicos de un sistema de bombeo utilizando la técnica de riego por surcos para el cultivo del frijol negro. Los resultados mostraron fluctuaciones esperadas en los parámetros hidráulicos como caudal, carga, potencia hidráulica, tiempo de bombeo y volumen bombeado. Se encontraron relaciones funcionales entre el caudal y la carga de bombeo, así como entre la potencia hidráulica, el caudal y la carga de bombeo. Estas relaciones pueden mejorar el funcionamiento del sistema de bombeo, ahorrar energía y aumentar la eficiencia de la bomba. Además, se desarrollaron funciones para predecir las curvas características de la carga, la eficiencia de la bomba y del sistema en general. Estos resultados pueden mejorar la eficiencia energética y la gestión del agua en la agricultura.