### Examinando por Autor "Salazar-Torres, J"

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Ítem Development of random thinking: Reflections and considerations(IOP Publishing, 2020) Salazar-Torres, J; Vera, M; Rincón, O; Omaña, L; Lizcano, L; Huérfano, Y; Vargas, DMás... This article discloses some considerations and reflections in the teaching of random thinking and data systems based on a documentary review. A documentary sample was used consisting of 40 documentary sources (articles, postgraduate dissertations and books), published in indexed journals, about random thinking. The research was based on a qualitative content analysis method which used the coding and categories saturation process. The results let us establish conceptual relationships considering three dimensions linked to the random thinking teaching, they are: epistemological corpus, theoretical corpus and the social function. The results allow to base new proposals of curricular, didactic and evaluative type for the teaching of this thinking, at the same time, it allows to carry out processes of self-assessment of the teaching practice and of the need that currently exists before the research in the classroom and the contextualization of mathematical knowledge.Más... Ítem Developmental perspectives of numerical thinking for the interpretation of physical quantities(IOP Publishing, 2020) Valbuena, O; Salazar-Torres, J; Díaz, J A; Rincón-Leal, O; Bravo, AMás... This research reveals the perspectives in the teaching of numerical thinking through a documentary review. The representation of physical elements such as functions, vectors and operators, and their subsequent interpretation through numerical thinking gives meaning to the physical quantities that such elements represent. A documentary sample integrated for 40 sources on numerical thinking such as articles published in indexed journals, postgraduate dissertations, and books is considered. A qualitative content analysis method is used. First, an encoding procedure is applied for tagging the extracted information from the source documents. Then, a split and merge procedure is considered in order to establish from the tags the dimensions and categories that allow determining the conceptual relationships that support the developmental perspectives of numerical thinking. The method reveals that the numerical thinking can be developed in the global context from four perspectives, namely, historical, theoretical, curricular, and social perspectives. From these results, an incorporation of the such perspectives can be institutionalized for promoting curricular, didactic and evaluative new proposals for numerical thinking teaching.Más... Ítem GeoGebra as learning tool for the search of the roots of functions in numerical methods(IOP Publishing, 2020) Arceo-Díaz, S; Briceo Barrios, E E; Aréchiga Maravillas, J; Salazar-Torres, JMás... Physics is capable of describing, through equations, phenomena on a micro and macroscopic scale. However, most of these equations are non-linear and the identification of their roots requires the use of approximation methods, with numerical methods being a proposal based on a systematic and iterative process, that conclude only when a pre-established tolerance is satisfied. Traditional teaching of numerical methods involves the memorization of algorithms. However, this hinders student’s ability to understand the important aspects and then apply them for solving applied problems in subjects such as kinematics, dynamics, electromagnetism, etc. Therefore, this work proposes the use of GeoGebra, as a didactic tool to illustrate the functioning of single root searching algorithms. By using the dynamical graphic’s view of GeoGebra, a series of abstract and applied problems where solved by engineering students taking a numerical methods course. The scores of this test group was then compared to a test group, taught trough algorithm memorization. Results show can improve their understanding of how the bisection, false position, secant, and Newton-Raphson methods are able to find approximated solutions to polynomial and trigonometric equations. The results are compared against traditional learning, based on memorizing the steps of the algorithm for each method and the representation of the convergence of successive roots by numerical tables.Más... Ítem Interest rates calculation in certain ordinary annuities(IOP Publishing, 2019) Flórez, M; Vera, M; Salazar-Torres, J; Huérfano, Y; Gelvez-Almeida, E; Valbuena, O; Vera, M I; Aranguen, MMás... Certain annuities are annuities whose payments occur on fixed dates; while a certain ordinary annuity is one in which payments are made at the end of each established period. The calculation of the interest rate, which governs the certain ordinary annuity, involves the use of a non-analytical equation that requires the application of numerical techniques to obtain the value of the aforementioned rate. The literature indicates that any of these techniques requires one or several numerical values for initialization, which generally are estimated using trial techniques, graphical methods or values present in pre-established tables. Through this article, a new robust methodology is proposed that calculates the useful numerical values to initialize the linear interpolation technique, which is used to calculate the interest rate linked to the certain ordinary annuity. The proposed methodology generates initialization values, one by default and the other by excess, which allow us to limit the value of the certain ordinary annuity interest rate considered. Finally, we generated a new strategy that constitutes a novel mathematical model for interest rates calculation in the context of certain ordinary annuity. The percentage relative error obtained indicates the excellent performance of the aforementioned mathematical model.Más... Ítem Large cells cancer volumetry in chest computed tomography pulmonary images(IOP Publishing, 2019) Huérfano, Y; Vera, M; Gelvez-Almeida, E; Vera, M I; Valbuena, O; Salazar-Torres, JMás... Lung cancer is the leading oncological cause of death in the world. As for carcinomas, they represent between 90% and 95% of lung cancers; among them, non-small cell lung cancer is the most common type and the large cell carcinoma, the pathology on which this research focuses, is usually detected with the computed tomography images of the thorax. These images have three big problems: noise, artifacts and low contrast. The volume of the large cell carcinoma is obtained from the segmentations of the cancerous tumor generated, in a semi-automatic way, by a computational strategy based on a combination of algorithms that, in order to address the aforementioned problems, considers median and gradient magnitude filters and an unsupervised grouping technique for generating the large cell carcinoma morphology. The results of high correlation between the semi-automatic segmentations and the manual ones, drawn up by a pulmonologist, allow us to infer the excellent performance of the proposed technique. This technique can be useful in the detection and monitoring of large cell carcinoma and if it is considering this kind of computational strategy, medical specialists can establish the clinic or surgical actions oriented to address this pulmonary pathology.Más... Ítem Learning the concept of integral through the appropriation of the competence in Riemann sums(IOP Publishing, 2020) Aréchiga Maravillas, J; Arceo-Díaz, S; Salazar-Torres, J; Sierra Andrade, D; Benites Montes, MMás... It is proposed that the difficulty of engineering students into understanding the concept of the integral, as a way for calculating the area under a curve, can be overcame if students are taught how to translate it into the problem of calculating a Riemann sum. A series of applied problems are proposed to provide a frame that required to calculate the area under a curve to two groups of students. For one of these groups, Geogebra was proposed as a tool that could be used to maintain the focus of students into the concepts, by providing ways to easily calculate and visualize the solutions, while the other group reached to the solutions by analytically making all the calculations. Evidence was found that, to a confidence level of 95%, Riemann sums calculated with Geogebra reduce the score difference in context problems requiring the calculation of integrals, helping students to reach a better understanding on the concept of the integral as the area under the curve of a given function.Más... Ítem Left atrial appendage automatic segmentation, in computed tomography images(IOP Publishing, 2019) Huérfano, Y; Vera, M; Vera, M I; Valbuena, O; Gelvez-Almeida, E; Salazar-Torres, J; Molina, VMás... The left atrial appendage is one of the anatomical places where most frequently blood thrombi occur. When migrating from the appendage, these thrombi, become blood emboli that, potentially, can compromise the physiology and/or anatomy of cardiac or cerebral blood vessels, being able to generate cerebrovascular events. The left atrial appendage segmentation is very difficult due, mainly, to its location and the identical densitometric information presents into of this appendage and around of the left atrium. In this paper, an automatic technique is proposed to segment this appendage with the purpose of generating important information to the procedure called left atrial appendage surgical closure. This information is linked to the volume and the diameters of the left atrial appendage. The technique consists of a digital pre-processing stage, based on filtering processes and definition of a region of interest and, of one segmentation stage that considers a clustering method. The results are promising and they allow us to calculate useful quantitative variables when characterizing the most lethal appendix of the human body represented by the mentioned appendage. These results are very important in clinical processes where both the shape and volume of this appendage are vital for detecting and monitoring some vascular diseases such as cardiac embolism, arterial hypertension and stroke, among others.Más... Ítem Mathematical argumentation in the classroom(IOP Publishing, 2019) Salazar-Torres, J; Vera, M; Contreras, Y; Gelvez-Almeida, E; Valbuena, O; Barrera, D; Rincón, OMás... The article shares some elements of comprehensive type about "mathematical argumentation in the classroom"; whose analysis, was made from two fundamental categories in the development of an oral mathematical argumentation process for the conviction, contradiction and validation of a written mathematical argumentation process. The research addressed two central categories of argumentation as a discursive form, the first one is the epistemic position, and the second one is the discursive position that students unveil at the time of mathematically arguing the solution to a problem situation. The research was developed under the interpretative paradigm through the design of a case study directed by the theory and technique of a focal group, for the collection of information. In the findings, difficulties in the passage were evidenced from the semantic to the theoretical from the epistemic position; regarding the discursive position, the presence of three discursive forms was revealed: description, explanation and argumentation, the latter being the least used by the students.Más... Ítem Newton-Raphson method initialization for non-analytical equations solution linked to anticipated annuities(IOP Publishing, 2019) Vera, M; Flórez, M; Salazar-Torres, J; Huérfano, Y; Gelvez-Almeida, E; Valbuena, O; Vera, M I; Aranguen, MMás... The series of payments made in equal intervals of time is known, in the world of financial mathematics, as an annuity. An anticipated annuity is one whose periodic payment expires at the beginning of the established payment interval. The non-analytical equation that allows us to calculate the interest rate, linked to the anticipated annuity, can be solved using several numerical methods, in particular, the numerical method called Newton-Rhapson. The main problem with this method is its initialization, which requires of one starting point that, usually, is estimated without any scientific background or using random or arbitraries mechanisms. In order to address this problem, in this paper, we establish as main objective to demonstrate that the Newton-Rhapson method can be initialized using only the data, of an anticipated annuity, identified as capital, income and payment intervals without the need to use the initialization strategies, reported in the literature. Through this article, a strategy is presented that allow us to calculate the value of the AA interest rate using the MNR. The value of the error generated for the problematic considered in order to assess the quality of the work performed, is a clear indicator of the good performance of the proposed strategy. This strategy for obtaining the starting point of the aforementioned numerical method is useful in the financial mathematical context, for example, when is necessary the interest rate calculation.Más... Ítem Problem solving strategy in the teaching and learning processes of quantitative reasoning(IOP Publishing, 2019) Barrera, D; Salazar-Torres, J; Vera, M; Gelvez-Almeida, EMás... The study presents an analysis of Polya's problem-solving strategy used in the training processes of quantitative reasoning competence in students of the Universidad Simón Bolívar, San José de Cúcuta, Colombia. The research was based on a descriptive design and had an intentional sample of 58 students who were studying the sciences and general competencies elective. For the collection of information, a diagnostic test (pre-test) and a final test (post-test) were applied, in order to check the incidence of the applied strategy. The results showed a significant improvement in the final results obtained by the students in each of the processes formed: interpretation, representation and modeling, and argumentation.Más... Ítem Pulmonary adenocarcinoma characterization using computed tomography images(IOP Publishing, 2019) Huérfano, Y; Vera, M; Valbuena, O; Gelvez-Almeida, E; Salazar-Torres, JMás... Lung cancer is one of the pathologies that sensitively affects the health of human beings. Particularly, the pathology called pulmonary adenocarcinoma represents 25% of all lung cancers. In this research, we propose a semiautomatic technique for the characterization of a tumor (adenocarcinoma type), present in a three-dimensional pulmonary computed tomography dataset. Following the basic scheme of digital image processing, first, a bank of smoothing filters and edge detectors is applied allowing the adequate preprocessing over the dataset images. Then, clustering methods are used for obtaining the tumor morphology. The relative percentage error and the accuracy rate were the metrics considered to determine the performance of the proposed technique. The values obtained from the metrics used reflect an excellent correlation between the morphology of the tumor, generated manually by a pneumologist and the values obtained by the proposed technique. In the clinical and surgical contexts, the characterization of the detected lung tumor is made in terms of volume occupied by the tumor and it allows the monitoring of this disease as well as the activation of the respective protocols for its approach.Más... Ítem Renal lithiasis detection in uro-computed tomography using a non-parametric technique(IOP Publishing, 2019) Rodríguez-Ibáñez, R; Vera, M I; Vera, M; Gelvez-Almeida, E; Huérfano, Y; Valbuena, O; Salazar-Torres, JMás... Renal lithiasis is the pathology that causes nephritic colic, which is one of the most frequent reasons for consultation in emergency medical services. According to the size, location, hardness and number of stones present in the urinary system, usually in the human kidney, it is established to which form of treatment is suitable for the patient. These kidney stones can be analyzed by means of biopsy or imaging modalities such as computed tomography images. This type of images has challenging problems called noise, artifacts and low contrast. In this paper, in order to address these problems, a non-parametric semi-automatic computational technique is developed for detecting kidney stones, present in computed tomography images, using digital image processing techniques based on a smoothing filter and an edge detector. Finally, the size and position of the stones present in the images are calculated and a precision metric is considered to compare the manual segmentation, performed by an urologist, and the one generated by the NPCT, obtaining an excellent correlation. This technique can be useful in the renal lithiasis detection and if it is considering this kind of computational strategy, medical specialists can establish the clinic or surgical actions oriented to address this pathology.Más... Ítem The rubric as an assessment strategy in the mathematical argumentation process(IOP Publishing, 2020) Salazar-Torres, J; Vera, M; Contreras, Y; Gelvez-Almeida, E; Huérfano, Y; Valbuena, OMás... The article shares the proposal of an analytical rubric as a strategy for the assessment and monitoring of learning outcomes in students who develop an argumentative plot from the mathematics field, to solve any problem situation in daily life. The study was based on the theory of mathematical argumentation proposed by Duval and the contributions of León and Calderón, as well as the dimensions presented to us by the logical frameworks in the design of analytical rubrics. The research was developed under the social critical paradigm through the design of pedagogical action research, and the focus group technique was used for the collection of information composed by five professors from the department of basic sciences. As a result, a collective rubric that, in addition to generating processes of self-assessment and self-training in teachers, evidences a decrease in the existent subjectivity of the evaluation processes, thus strengthening its objectivity.Más... Ítem Semi-automatic detection of hepatic tumor in computed tomography images(IOP Publishing, 2019) Sáenz, F; Vera, M; López, J; Huérfano, Y; Valbuena, O; Vera, M I; Gelvez-Almeida, E; Salazar-Torres, JMás... In this work, the main purpose is develop a computational segmentation strategy for liver tumor semiautomatic detection. This strategy considers three-dimensional computed tomography images and it consists of techniques application that, on the one hand, diminish the noise and detect the edges of the objects present in those images and, on the other hand, generate the liver tumor morphology. For this, the sequence of techniques composed of gaussian smoothing, gradient magnitude, median filter, region growing and binary morphological dilation are used. The value obtained, for the metric called Dice score, show a good correlation between manual segmentation, performed by a hepatologist, and the tumor segmentation obtained using the proposed technique. This type of segmentation is the extreme utility for the characterization of hepatic tumors and the planning of the clinical behavior to be followed in the treatment of this human liver disease.Más... Ítem Smart operator for the human liver automatic segmentation, present in medical images(IOP Publishing, 2019) Vera, M; Sáenz, F; Huérfano, Y; Gelvez-Almeida, E; Vera, M I; Salazar-Torres, J; Valbuena, OMás... The segmentation of the human body organ called liver is a highly challenging problem due to the noise, artifacts and the low contrast exhibited by the anatomical structures located around the liver and that are present in digital images, generated by any modality of medical images. The main modalities are: ultrasound, nuclear emission, magnetic resonance and the gold standard called multi-slice computed tomography. In this paper, with the objective of to address this problem, we consider multi-slice computed tomography images and we propose an automatic strategy based on two phases. In the first phase, a digital filtering bank is used for diminishing the noise effect and the artifacts impact in the quality of images. In the second phase, called liver detection, we use a smart operator based on least squares support vector machines for generating both the morphology and the volume of liver. The application of this strategy allows generating the morphology of the liver in a precise and efficient manner as it was demonstrated by the metrics used to assess its performance. These results are very important in clinical-surgical processes where both the shape and volume of liver are vital for monitoring some liver diseases that can affect the normal liver physiology.Más... Ítem Space-occupying lesions identification in mammary glands using a mixed computational strategy(IOP Publishing, 2019) Vargas, S; Vera, M I; Vera, M; Salazar-Torres, J; Huérfano, Y; Valbuena, O; Gelvez-Almeida, EMás... Abstract. The mammary pathology can manifest itself in multiple ways and originates spaceoccupying lesions. The breast cancer is a space-occupying lesion, which is highly prevalent, especially in women, and worldwide it is one of the leading causes of morbidity and mortality in this population. The main image modality for breast cancer detection is the magnetic resonance but this kind of image modality introduces several imperfections that affect the image quality. Some of these imperfections or problems are: inhomogeneity in the anatomical structures, riccian noise and artifacts. These problems make the analysis of the image information a real challenge. To address these problems, in this paper, we propose a computational technique able to extract a space-occupying lesion linked to breast cancer, present in magnetic resonance images. For this, the original image is processed with statisticalarithmetic filters and segmentation algorithms based on thresholding and multi-seed region growing techniques. The results, based on Dice score, show that the proposed technique is suitable for segmenting the breast cancer due high correlation between semi-automatic and manual segmentations. This technique can be useful in the detection, characterization and monitoring of this type of cancer and it can let to medical doctors to realize their work more efficiently.Más... Ítem Testing GeoGebra as an effective tool to improve the understanding of the concept of limit on engineering students(IOP Publishing, 2019) Aréchiga Maravillas, J C; Arceo Díaz, S; Salazar-Torres, J; Sierra Andrade, D AMás... The impact GeoGebra on the teaching of the concept of limit was analyzed. Two groups of engineering students, studying differential calculus, served as control and test groups. The traditional teaching, based on examples solved by hand, was given to the control group while a series of activities involving the usage of the mathematical software GeoGebra were applied in an attempt of improving the degree of assimilation on the concept of limits.Más... Ítem Trans-complexity: a management fad or a mathematical construct(IOP Publishing, 2020) Bravo, A; Salazar-Torres, J; Madriz, D; Vergel-Ortega, M; III Workshop on Modeling and Simulation for Science and EngineeringMás... Trans–complex organizations concept has been introduced in the management science, even becoming an object of study. In the global context, definitions, concepts, research and philosophical or practical proposals have emerged for the understanding of organizations from a trans-complex perspective. In this work, a critical position of trans-complexity is presented as a historical discovery that associates a new characterization of phenomena: for example, in exchange for trans–complex organizations, a trans-complex epistemic vision of social organizations is proposed. Thus, the trans-complexity is ratified not as a quality, but as a requirement of epistemic order of scientific research. From this perspective, that complex organization can be explained through elements such as uncertainty, chaos and self-organization, with an epistemological explanation of systems theory, decision theory and dynamic systems theory. This paper shows the trans-complexity more than a management fad, an analysis model or a management topic, as an element to be incorporated by researchers in the construction of theoretical frameworks and methodical designs of their researches in order to purpose significant contributions to science, and to the organization itself, based on such important mathematical theories.Más... Ítem Use of computational realistic models for the cardiac ejection fraction calculation(IOP Publishing, 2019) Huérfano, Y; Vera, M; Vera, M I; Valbuena, O; Gelvez-Almeida, E; Salazar-Torres, JMás... Ejection fraction is one of the most useful clinical descriptors to determine the cardiac function of a subject. For this reason, obtaining the value of this descriptor is of vital importance and requires high precision. However, in the clinical routine, to generate the mentioned descriptor value, a geometric hypothesis is assumed, obtaining an approximate value for this fraction, usually by excess, and which is a dependent-operator. The aim of the present work is to propose the accurate calculation of the ejection fraction from realistic models, obtained computationally, of the cardiac chamber called right ventricle. Normally, the geometric hypothesis that makes this ventricle coincide with a pyramidal type geometric shape, is not usually, fulfilled in subjects affected by several cardiac pathologies, so as an alternative to this problem, the computational segmentation process is used to generate the morphology of the right ventricle and from it proceeds to obtain, accurately, the ejection fraction value. In this sense, an automatic strategy based on no-lineal filters, smart operator and region growing technique is propose in order to generate the right ventricle ejection fraction. The results are promising due we obtained an excellent correspondence between the manual segmentation and the automatic one generated by the realistic models.Más... Ítem Usefulness of cutting planes in the hierarchical segmentation of cardiac anatomical structures(IOP Publishing, 2019) Vera, M; Valbuena, O; Huérfano, Y; Vera, M I; Gelvez-Almeida, E; Salazar-Torres, JMás... A spatial geometric plane is defined by the three-dimensional coordinates of a pair of spatial points and the direction that the normal vector establishes, which is formed by joining those points by means of an oriented line segment. This type of planes, in three-dimensional images, is extremely useful as an alternative solution to the problem of low contrast that exhibit the anatomical structures present in cardiac computed tomography images. To do this, after using a predetermined filter bank and in order to define a region of interest, a smart operator based on least squares support vector machines is trained and validated in order to detect the aforementioned coordinates which enables the location of the plane, in the three-dimensional space that contains the considered images. Once the structure that is required to segment is identified, a discriminant function is used that cancels all information not linked to this structure. In this work, the segmentation of the left ventricle, based on region growing technique, is firstly considered and then the left atrium is segmented considering region growing technique and an inverse discriminant function. The results show an excellent correspondence relationship when the spatial union of both structures is made.Más...