Examinando por Materia "analysis"
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Ítem Adaptive LAMDA applied to identify and regulate a process with variable dead time(Institute of Electrical and Electronics Engineers Inc., 2020-01-01) Morales L.; Pozo D.; Aguilar J.; Rosales A.; Universidad EAFIT. Departamento de Ingeniería de Sistemas; I+D+I en Tecnologías de la Información y las ComunicacionesIn this paper, an adaptive intelligent controller based on the fuzzy algorithm called LAMDA (Learning Algorithm for Multivariable Data Analysis) is presented in order to identify and regulate a process with variable dead time. The original algorithm has been used for supervised and unsupervised learning, whose main field of application is the identification of functional states of the systems. In this work a modification of LAMDA has been implemented which is capable of online learning using hybrid techniques. The proposal consists of two stages: training stage to learn about the unknown plant in order to establish initial parameters to the controller, and a second phase, called application, in which the control strategy is updated using online learning. The proposed method is tested in the control objective of regulation of a process with variable dead time, to analyze the viability of its utilization in these types of systems in which their dynamics are variable and unknown. © 2020 IEEE.Ítem APPLIES: A framework for evaluAting organization's motivation and preparation for adopting product lines(IEEE Computer Society, 2018-01-01) Rincón, L.; Mazo, R.; Salinesi, C.; Universidad EAFIT. Departamento de Ingeniería de Sistemas; I+D+I en Tecnologías de la Información y las ComunicacionesIn the software industry, product Lines has emerged as an attractive approach to perform planned reuse. Nevertheless, a product line solution is not appropriate for all the cases and requires some conditions to be implemented successfully. The literature offers several contributions regarding the adoption of product lines. However, only a few of these support decision-makers for taking well-informed decisions in favor or against following this approach. This paper presents APPLIES, a framework to (i) detect signals that could motivate an organization to adopt a product line approach (ii) assess to what extent a company is prepared for supporting the practices necessary to adopt a product line. APPLIES is grounded in a thematic analysis of the literature and was preliminarily evaluated with two experts through a survey and an interview. The results of the evaluation provide us insights to create an improved version of the proposal following a design-science method. © 2018 IEEE.Ítem A domain-specific modeling framework for attack surface modeling(SciTePress, 2020-01-01) Sun, T.N.; Drouot, B.; Golra, F.R.; Champeau, J.; Guerin, S.; Le Roux, L.; Mazo, R.; Teodorov, C.; Van Aertryck, L.; L'Hostis, B.; Universidad EAFIT. Departamento de Ingeniería de Sistemas; I+D+I en Tecnologías de la Información y las ComunicacionesCybersecurity is becoming vital as industries are gradually moving from automating physical processes to a higher level automation using cyber physical systems (CPS) and internet of things (IoT). In this context, security is becoming a continuous process that runs in parallel to other processes during the complete life cycle of a system. Traditional threat analysis methods use design models alongside threat models as an input for security analysis, hence missing the life-cycle-based dynamicity required by the security concern. In this paper, we argue for an attacker-aware systems modeling language that exposes the systems attack surfaces. For this purpose, we have designed Pimca, a domain specific modeling language geared towards capturing the attacker point of view of the system. This study introduces the formalism along with the Pimca workbench, a framework designed to ease the development and manipulation of the Pimca models. Finally, we present two relevant use cases, serving as a preliminary validation of our approach. © Copyright 2020 by SCITEPRESS - Science and Technology Publications, Lda. All rights reserved.Ítem Enhanced molecular visualization of root colonization and growth promotion by Bacillus subtilis EA-CB0575 in different growth systems(Elsevier GmbH, 2018-01-01) Posada, L.F.; Álvarez, J.C.; Romero-Tabarez, M.; de-Bashan, L.; Villegas-Escobar, V.; Universidad EAFIT. Departamento de Ciencias; Biodiversidad, Evolución y ConservaciónBacillus subtilis EA-CB0575 is a plant growth-promoting bacterium (PGPB) associated with banana and tomato crops. Root colonization is an important trait for PGPB microorganisms and potentiates the bacterial effect related to the mechanisms of plant growth promotion. Therefore, detection of bacterial colonization of roots in different culture systems is important in the study of plant–microorganism interactions. In this study, fluorescent in situ hybridization (FISH) and catalyzed reporter deposition–FISH (CARD–FISH) were evaluated to determine the colonization ability of B. subtilis EA-CB0575 on banana and tomato roots planted on solid and liquid Murashige and Skoog medium (MS(S) and MS(L), respectively) and in soil for tomato plants. Results showed B. subtilis colonization 0–30 days post inoculation for banana and tomato plants in different culture systems with differential distribution of bacterial cells along tomato and banana roots. FISH and CARD–FISH methodologies were both successful in detecting B. subtilis colonies, but CARD–FISH proved to be superior due to its enhanced fluorescence signal. The presence of bacteria correlated with the promotion of plant growth in both plant species, providing clues to relate rhizospheric colonization with improvement in plant growth. FISH and CARD–FISH analysis results suggested the presence of native microbiota on the roots of in vitro banana plants, but not on those of tomato plants. © 2018 Elsevier GmbHÍtem Implementing an active learning platform to support student learning in a numerical analysis course(Institute of Electrical and Electronics Engineers Inc., 2017-01-01) Zabala F.J.C.; Parker H.E.; Vieira C.; Universidad EAFIT. Departamento de Ingeniería de Sistemas; I+D+I en Tecnologías de la Información y las ComunicacionesClassroom instruction in the 21st century needs to incorporate innovative, research-based pedagogies. The engineering classroom is currently experiencing a shift towards more active learning activities due to both advances in educational research, and advances in technologies that enable practices such as the flipped classroom model. Given that course transformation is a gradual process that begins at the level of the instructor, educators need access to the essential tools and training in order to introduce these changes into the curricula. This paper introduces a course re-design based on Self-Determination Theory and Constructivism; and outlines effectively implemented active learning strategies using the flipped classroom model. The data were collected from a Numerical Analysis course, which is an important course across several engineering disciplines at Universidad EAFIT. This course enables engineering students to solve complex problems using mathematical and computational methods. This paper describes the implementation of an online active learning platform called "Numérico Interactivo" for two related engineering courses: Numerical Analysis (NA) and Numerical Processes (NP). The platform was available to all students, but only NA implemented it using a flipped classroom model. NP made the platform available as an optional course tool. Informed by SDT principles, "Numérico Interactivo" includes a variety of instructional materials such as explanations, examples, frequently asked questions (FAQ), self-assessment tools, and evaluation. This study compares the two courses in terms of: (1) students' perceptions about the instructional materials of the course; (2) students' use of the platform; and (3) students' perceived usefulness of the different elements within the platform. Results suggest that students in the NA course found the classroom sessions and the homework assignments more useful as compared to the students enrolled in the NP course. In addition, in the NA course students used the platform more often for class preparation and to study before each module. The way in which the platform was implemented in NA also increased student motivation in the course. Overall, the results suggest that "Numérico Interactivo" is useful to implement course re-designs into engineering and computing education courses, but such tools need to be guided by active learning practices so that students can fully benefit from them. © 2017 IEEE.Ítem International SMEs from emerging markets-Insights from the Colombian textile and apparel industry(Springer New York LLC, 2016-03-01) Gonzalez-Perez, Maria Alejandra; Manotas, E.C.; Ciravegna, L.The internationalization of firms from emerging markets has been studied mainly from the perspective of large firms. Smaller and younger international firms based in emerging markets suffer from underrepresentation in the literature. This study sheds light on the internationalization of emerging market SMEs, focusing on Colombian textile and apparel exporters. Using mixed research methods, it illustrates the role of firm age in influencing internationalization strategy. It examines 1165 export contracts by 50 SMEs, discussing export intensity, speed, and geographic scope using recurrence analysis and cluster analysis. It contributes to international entrepreneurship by exploring new empirical evidence and examining it using a novel methodological approach.Ítem Technological tools to learn calculus(Institute of Electrical and Electronics Engineers Inc., 2015-12-02) Gómez, G.P.P.; Restrepo, C.M.Z.; Duarte, P.V.E.; Rivera, L.F.Z.; Universidad EAFIT. Departamento de Ingeniería de Sistemas; I+D+I en Tecnologías de la Información y las ComunicacionesOnline learning tools have allowed professors to carry out their classes in an interactive way, synchronic as well as asynchronic, giving them the opportunity to explore from different points of view specific themes or concepts, achieving greater dynamism in their classes through the active participation of students. This article presents the results of the implementation of an software tool for massive use designed with the objective of allowing Engineering students to strengthen their basic mathematical knowledge as well as to improve their results in courses such as Calculus I and Mathematics I. These courses are part of the first semesters of the syllabus for all undergraduate programs of the School of Engineering, and are basic courses in the formation of an engineer at Universidad EAFIT (Medellin, Colombia). This software tool for massive use allows students to self-diagnose, to solve exercises with different levels of complexity and difficulty, to visualize academic contents such as video classes and virtual resources, and to know their evolution in the understanding of basic concepts in calculus. On one hand, this facilitates the beginning of their studies at the university. On the other, it gives the professor an initial diagnose of the level students have to start the course so that continuous analytics can be performed based on the learning process of the student. Furthermore, this article shows the results of a comparative analysis done to two groups of students, a Control group and an Experimental group, that took Calculus I as part of their undergraduate studies. The experiment lasted two months with testing done at the beginning and at the end of the course. The objective was to register the level of knowledge acquired by the students and compare the differences between the two groups, control and experimental. The testing also allowed the progress of the student between tests to be measured, taking into account that the experimental group had the opportunity to explore the platform during this two-month period. Therefore, the analysis performed served to gather information useful for evaluating the effectiveness of the proposed system in the learning process of the students at the University. © 2015 IEEE.Ítem Unsupervised fuzzy binning of metagenomic sequence fragments on three-dimensional Barnes-Hut t-Stochastic Neighbor Embeddings(Institute of Electrical and Electronics Engineers Inc., 2018-01-01) Ariza-Jimenez L.; Quintero O.L.; Pinel N.; Universidad EAFIT. Departamento de Ciencias; Biodiversidad, Evolución y ConservaciónShotgun metagenomic studies attempt to reconstruct population genome sequences from complex microbial communities. In some traditional genome demarcation approaches, high-dimensional sequence data are embedded into two-dimensional spaces and subsequently binned into candidate genomic populations. One such approach uses a combination of the Barnes-Hut approximation and the t -Stochastic Neighbor Embedding (BH-SNE) algorithm for dimensionality reduction of DNA sequence data pentamer profiles; and demarcation of groups based on Gaussian mixture models within humanimposed boundaries. We found that genome demarcation from three-dimensional BH-SNE embeddings consistently results in more accurate binnings than 2-D embeddings. We further addressed the lack of a priori population number information by developing an unsupervised binning approach based on the Subtractive and Fuzzy c-means (FCM) clustering algorithms combined with internal clustering validity indices. Lastly, we addressed the subject of shared membership of individual data objects in a mixed community by assigning a degree of membership to individual objects using the FCM algorithm, and discriminated between confidently binned and uncertain sequence data objects from the community for subsequent biological interpretation. The binning of metagenome sequence fragments according to thresholds in the degree of membership opens the door for the identification of horizontally transferred elements and other genomic regions of uncertain assignment in which biologically meaningful information resides. The reported approach improves the unsupervised genome demarcation of populations within complex communities, increases the confidence in the coherence of the binned elements, and enables the identification of evolutionary processes ignored in hard-binning approaches in shotgun metagenomic studies. © 2018 IEEE.