Examinando por Materia "Segmentation"
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- PublicaciónSólo datosA Note on the Phase Congruence Method in Image Analysis(Lecture Notes in Computer Science, 2019-03-03) Forero Vargas, Manuel Guillermo; Jacanamejoy, Carlos A.Phase congruence technique developed by Kovesi allows the detection of edges in images by analyzing the phases of their frequency components. A limitation of this technique is that it does not allow the detection of closely spaced edges that have different intensities. However, this situation occurs frequently in images, which therefore limits the use of this method. This study aims to propose a method that can overcome this limitation. Unlike the original technique, the proposed study uses a high degree of overlap between different frequency components to allow the detection of contiguous edges of low intensity. To avoid the problems that arise from high overlap, we modify the sensitivity of the phase congruence, allowing us to detect weak edges while discarding the noise associated with the proposed changes. We present our results and compare them with the results obtained using the existing technique.
- PublicaciónSólo datosA Tuning Method for Diatom Segmentation Techniques(Applied sciences, 2017-07-27) Rojas Camacho, Oswaldo; Forero, Manuel G.; Menéndez, José ManuelPhytoplankton such as diatoms or desmids are useful for monitoring water quality. Manual image analysis is impractical due to the huge diversity of this group of microalgae and its great morphological plasticity, hence the importance of automating the analysis procedure. High-resolution images of phytoplankton cells can now be acquired by digital microscopes, which facilitate automating the analysis and identification process of specimens. Therefore, new systems of image analysis are potentially advantageous compared to manual methods of counting for solution identification. Segmentation is an important step in the analysis of phytoplankton images. Many standard techniques like thresholding and edge detection are employed in the segmentation of diatoms and other phytoplankton, which are crucial organisms in microscopy images. However, in general, they require several parameters to be fixed beforehand by the user in order to get the best results. This process is usually done by comparing results and looking for the best parameters. To automatize this process, we propose an automatic tuning method to find the optimal parameters in an iterative procedure, called Parametric Segmentation Tuning (PST). This technique compares successive segmentation results, choosing the ones that gets the maximal similarity. In this paper, tuning is formulated as an optimization problem using a similarity function within the solution space. This space consists of the set of binary images that are generated by the segmentation technique to be tuned, where these binary images are seen as a function of the original images and the segmentation parameters. The PST technique was tested with two of the most popular techniques employed to segment phytoplankton images: the Canny edge detection and a binarisation method. The results of the thresholding technique were validated by comparing them to those of the Otsu method and the Canny method with a ground truth. They show that PST is effective to find the best parameters.
- PublicaciónAcceso abiertoEstudio de caracterización de la demanda del servicio de fabricaciones especiales en el sector agrícola del municipio del Espinal (Tolima) para la empresa Tornitolima en el año 2018(Universidad de Ibagué, 2018) Lozano Campos, Yaritza; García Ortiz, Paula AndreaThis project was based on a characterization of the demand of the special manufacturing pieces service for the agricultural sector of Espinal-Tolima, it was developed for the company Tornitolima Ltda. that has been in Ibague market for twenty-five years. This investigation was justified due to the need shown by the company in the search for alternatives for its growth and its expansion to new market routes, this in order to face changes in the market and accelerated competition in the hardware stores sector in Ibagué city, therefore, the municipality of Espinal-Tolima was nominated as the first analysis option to know and evaluate the market potential for this purpose. This study was framed in a descriptive research of transversal type with quantitative character, likewise, for its modeling, the methodology that was used as a method of gathering information the instrument called face-to-face questionnaire, of which two interviews were applied to experts and through a non-sampling probabilistic nineteen structured questionnaires from a sample of thirty-two agricultural companies were applied. In this way it was possible to conclude that the agricultural sector of Espinal-Tolima is a potential and significant segment for the company as the first measure for its expansion at departmental level and above all for its positioning, because, favorable results were found that point from the high necessity of the service of special fabrications and the opening of a branch in Espinal by the company Tornitolima Ltda., among others opportunities.
- PublicaciónAcceso abiertoEstudio de mercado para evaluar el impacto económico que ha tenido la construcción de la variante de Melgar 2017(Universidad de Ibagué, 2019) Díaz Jiménez, Yenny Paola; Yate Vela, Ingrid PaolaThe purpose of this degree work was to evaluate the economic impact of the construction of the Melgar 2017 variant, according to the perception of the inhabitants and merchants of the municipality, in the event that they identify with the variant positively or negatively in tourism and its economy, in this way, we have made each of the public and private entities to improve tourism in the municipality.
- PublicaciónSólo datosEvaluation of Some Ingredients and Energy Content on Front-of-Pack Cereal Bar Labeling as Drivers of Choice and Perception of Healthiness: A Case Study with Exercisers(Journal of Food Science, 2019-07-29) Salazar, Natalia A.; Fiszman, Susana; Orrego, Carlos E.; Tarrega, AmparoThe objective of this study was to explore the drivers of choice and perceptions of healthiness that specific ingredient or energy content information displayed on the front-of-pack label of cereal bars triggers among different groups of consumers. The participants (18 to 50 years old), classified as exercisers (n = 103, 52 women) or nonexercisers (n = 101, 51 women), completed a questionnaire and then rated their interest using images of cereal bars that varied in four characteristics (“With fruit,” “With chocolate,” “High protein,” and calorie content). Conjoint analysis showed that the most important motives were associated with the convenience, pleasure/indulgence and liking dimensions, which did not differ between groups. These were followed by two other motives introduced in this study: energy/physical activity and satiety, in which the exercisers showed a distinctively higher level of interest than the nonexercisers. Chocolate and a low calorie content were the outstanding drivers of interest, at similar levels for both groups. A high protein content claim increased the interest of all participants, but more so for exercisers and for men. Fruit had a low impact on interest, which was only significant for women. These results indicate that front-of-pack label information influences choice in a distinctive way for some targeted population groups. Practical Application: This study contributes knowledge about the impact that front-of-pack label information about certain ingredients and the energy content has on the motives and drivers for snack choices and perceptions of healthiness. The results contribute interesting results on the behavior of some consumer segments, in particular, exercisers and people involved in fitness activities, who are supposed to have special dietary needs. © 2019 Institute of Food Technologists®
- PublicaciónSólo datosFeature relevance in dermoscopy images by the use of ABCD standard(Proceedings of SPIE - The International Society for Optical Engineering, 2020-08-24) Pulido, Sergio D.; Bocanegra, Alvaro J.; López, Juan M.; Forero, Manuel G.; Cancino, Sandra L.The use of complex classification algorithms such as deep learning techniques does not allow the researchers to identify the most discriminant features for tumor classification as they lack interpretability. This study aims to develop an algorithm capable of differentiating a set of dermoscopic images depending on whether the tumor is benign or malignant. The priority of this research is to obtain the importance of each extracted feature. This work is focused on the ABCD rule feature analysis and it aims to find the relevance of each feature and its performance in a classification model. A relevant aspect of this study is the use of a heterogeneous database, where the images were uploaded by different sources worldwide. A combination of novel and previously used features are analyzed and their importance is computed by the use of a Gaussian mixture model. After selecting the most discriminant features, a set of classification models was applied to find the best model with the less quantity of features. We found that a total of 65.89% of the features could be omitted with a loss in accuracy, sensibility and specificity equal or lower than 2%. While similar performance measures have been employed in other studies, most results are not comparable, as the databases used were more homogeneous. In the remaining studies, sensitivity values are comparable, with the main difference that the proposed model is interpretable.
- PublicaciónAcceso abiertoPlan de mejoramiento para las cargas laborales de los auxiliares de enfermería en un turno diurno en el área de observación, del servicio de urgencias en la Clínica Tolima S.A.(Universidad de Ibagué, 2020) Hernandez Garcia, Angie Estefany; Garcia Acosta, Erika Lucia; Pérez Vargas, Carlos AndrésThe present improvement plan for the workloads of nursing assistants on a day shift in the observation area, of the emergency service at the Tolima SA Clinic, aims to analyze the aspects and / or internal and external factors that directly affect and indirectly the position. For which a series of key methods referring to the measurement of work were implemented, which made it possible to measure the workload of the worker and also detect the problems of work overload that were occurring, to finally be able to design through an improvement plan the appropriate strategies to end thes.
- PublicaciónSólo datosSegmentation of Meristem Cells by an Automated Optimization Algorithm(Applied Sciences, 2020-11-28) Rojas, Oswaldo; Forero Vargas, Manuel Guillermo; Menéndez, José Manuel; Jones, Angharad; Dewitte, Walter; Murray, JamesMeristem cells are irregularly shaped and appear in confocal images as dark areas surrounded by bright ones. Images are characterized by regions of very low contrast and absolute loss of edges deeper into the meristem. Edges are blurred, discontinuous, sometimes indistinguishable, and the intensity level inside the cells is similar to the background of the image. Recently, a technique called Parametric Segmentation Tuning was introduced for the optimization of segmentation parameters in diatom images. This paper presents a PST-tuned automatic segmentation method of meristem cells in microscopy images based on mathematical morphology. The optimal parameters of the algorithm are found by means of an iterative process that compares the segmented images obtained by successive variations of the parameters. Then, an optimization function is used to determine which pair of successive images allows for the best segmentation. The technique was validated by comparing its results with those obtained by a level set algorithm and a balloon segmentation technique. The outcomes show that our methodology offers better results than two free available state-of-the-art alternatives, being superior in all cases studied, losing 9.09% of the cells in the worst situation, against 75.81 and 25.45 obtained in the level set and the balloon segmentation techniques, respectively. The optimization method can be employed to tune the parameters of other meristem segmentation methods.