Manizales, Colombia

Catholic University of Manizales

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Sierra-Alonso E.F.,National University of Colombia | Cardona-Morales O.,Catholic University of Manizales | Castellanos-Dominguez G.,National University of Colombia
Proceedings of ISMA 2016 - International Conference on Noise and Vibration Engineering and USD2016 - International Conference on Uncertainty in Structural Dynamics | Year: 2016

In this paper acoustic and vibration signals are analyzed under different types of faults to characterize the machine condition. To this end, the proposed methodology comprises three stages including signal enhancement, feature extraction, and fault classification. Firstly, a filter bank methods decompose both signals into several spectral-band spectral components, in particular, empirical mode decomposition, wavelet packet transform, and Fourier-based filtering are employed. Secondly, a set of similarity measures computes the mutual statistical dependence between each limited-bandwidth component and the raw signal. Lastly, the characterized signals are classified identifying faults in rolling element bearing and shaft defects. The robustness of our approach is validated contaminating the signal with several levels of additive white Gaussian noise. As a result, the proposed detection based on filter bank similarity features is a promising methodology to implement in condition monitoring of rotating machinery when the measurements have a low SNR ratio.


Gutierrez-Perez R.B.,Catholic University of Manizales | Salgado M.L.,Catholic University of Manizales
Revista de Salud Publica | Year: 2016

Objective To determine the prevalence of subclinical thyroid dysfunction in the student community of Universidad Católica in Manizales. Materials and Methods Descriptive cross-sectional study in which 160 students of Universidad Católica in Manizales participated during 2012 and 2013; these students were educated through an advertising strategy about thyroid dysfunction and then a survey was applied. Informed consent was obtained and medical evalua tion of nodules and goiter, blood sampling, processing and determination of thyroid stimulating hormone (TSH) were performed. Results A correspondence analysis (optimal scaling) established that related variables such as average body mass index (BMI) 24.12 (normal 18.5 to 24.99), female gender (87.5 %), and mixed race (61 %) showed high correspondence with the normal values of thyroid stimulating hormone (TSH) according to the values provided by the trading house (0,39-6,16 μIU/ml) and the age range 20-25 years (50 %). No evidence of a relation between family history, presence of goiter and nodules was found. Conclusions Student population Universidad Católica in Manizales did not present subclinical thyroid dysfunction. © 2016, Universidad Nacional de Colombia. All rights reserved.


Marquez M.C.,Catholic University of Manizales | Chacon-Cardona J.A.,Catholic University of Manizales
Revista de Salud Publica | Year: 2016

Objective To establish the correlation between the methods of Wintrobe and micro-hematocrit Methods 407 patients attendees were taken laboratory to third level simultaneo usly tests were performed in the study. Results Using a statistical method of linear regression correlation coefficient of 0,99 was found. Conclusion Both methods can contribute to the clinical analysis of patients who were asked to test for diagnosis or control of different pathologies. © 2016, Universidad Nacional de Colombia. All rights reserved.


Estrada-Salazar G.I.,Catholic University of Manizales | Chacon-Cardona J.A.,Catholic University of Manizales
Revista de Salud Publica | Year: 2016

Objective To determine the frequency of ringworm in people of different social care institutions in the city of Manizales in 2011. Method Using the sampling sites that had some kind of suspicious lesion from a cutaneous mycosis, direct analysis with KOH and culture media was Saboureaud and Mycosel. An instrument of data collection was used to establish factors associated with the presence of these microorganisms. Results The yeast found most frequently were: Candida albicans, Trichosporon sp and Penicillium molds saprophytes sp, Fusarium sp, followed by dermatophyte fungi such as Trichophyton mentagrophytes, Trichophyton rubrum, Epidermophyton floccosum and Microsporum gypseum. Dry scaly lesions were found more frequently. The shared bathrooms and living in overcrowded and the use of common elements were the most important in this study associated factors. Conclusions Dermatomycoses are common in vulnerable populations and are associated with different very similar to those found in other studies of the same nature factors. © 2016, Universidad Nacional de Colombia. All rights reserved.


Mulcue-Nieto L.F.,Catholic University of Manizales | Mulcue-Nieto L.F.,International University of Andalusia | Mulcue-Nieto L.F.,University of Malaga | Mora-Lopez L.,International University of Andalusia | Mora-Lopez L.,University of Malaga
Applied Energy | Year: 2015

Photovoltaic applications are implemented on a large scale in buildings, with a view to reducing global warming sustainably, as well as to meet energy demand. Thousands of electricity generators have been installed in this process around the world. However, very few countries have technical regulations that enable the energy efficiency and yield to be optimised in building-integrated photovoltaics (BIPV). On the other hand, all these normative should be a result of a serious study of the solar resource available in each region.This paper proposes a methodology to establish technical standards in order to limit the losses due to shading and orientation of the constructed surface areas, where any country could be taken as benchmark. Colombia is also taken as a case study, by performing a comparative analysis for different cities. © 2014 Elsevier Ltd.


Mulcue-Nieto L.F.,Catholic University of Manizales | Mulcue-Nieto L.F.,International University of Andalusia | Mora-Lopez L.,International University of Andalusia | Mora-Lopez L.,University of Malaga
Solar Energy | Year: 2014

The use of photovoltaic solar energy is a growing reality worldwide and its main objective is to meet electricity demand in a sustainable manner. The so-called Grid-Connected Photovoltaic Power Systems (GCPS) prevail in urban zones, together with Building-integrated Photovoltaics (BIPV); whose performance and energy efficiency depends on different factors. The main aspects include those related to the solar radiation available in the geographical location of the facility, the climate, the orientation and tilt of the used surfaces, the appropriate design of the system and the quality of the components. Therefore, several methods have been proposed to try to predict the influence of the aforementioned variables on the amount of electricity produced. However, the majority are very tedious to implement or do not take the specific characteristics of the system into account.This paper proposes a simple and reliable expression, which can be used in low latitude countries. The case study is likewise performed for Colombia, with a comparative analysis for different cities of the angular losses and due to dirt, the losses due to temperature, the DC-AC conversion losses and the Performance Ratio of the system (PR). © 2014 Elsevier Ltd.


Cardona-Morales O.,Catholic University of Manizales | Castellanos-Dominguez G.,National University of Colombia
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) | Year: 2016

Condition monitoring of mechanical systems is an important topic for the industry because it helps to improve the machine maintenance and reduce the total operational cost associated. In that sense, the vibration analysis is an useful tool for failure prevention in rotating machines, and its main challenge is estimating on-line the dynamic behavior due to non-stationary operating conditions. Nevertheless, approaches for estimating time-varying parameters require the shaft speed reference signal, which is not always provided, or are oriented to off-line processing, being not useful on industrial applications. In this paper, a novel Order Tracking (OT) is employed to estimating both the instantaneous frequency (IF) and the spectral component amplitudes, which does not require the shaft speed reference signal and may be computed on-line. In particular, a nonlinear filter (Square-Root Cubature Kalman Filter) is used to estimate the spectral components from the vibration signal that provide the necessary information to detect damage on a machine under time-varying regimes. An optimization problem is proposed, which is based on the frequency constraints to improve the algorithm convergency. To validate the proposed constrained OT scheme, both synthetic and real-world application are considered. The results show that the proposed approach is robust and it successfully estimates the order components and the instantaneous frequency under different operating conditions, capturing the dynamic behavior of the machine. © Springer International Publishing Switzerland 2016.


Within the activities for quality control in the laboratory, the final results of a particular analyte are now recognized as intermediates, due to the relevance given to quality assurance, as the ultimate goal of programs for quality management. This concept makes it necessary to establishment of integral tools, to detect events such as cross-contamination, and measures to avoid affecting the analysis method. Objective: to established a system for monitoring and control of crosscontamination in the laboratory of microbiological analysis of food. Materials and methods: Flowcharts were developed to control the proceedings on the populations of aerobe mesophilics and molds originated from pollution in the environment, surfaces, sterile material and culture media, which included a decision tree designed to perform control actions based on tolerance intervals, which were established as objective tool to decision-making leading to normalize counts of microbial populations in question. Results: Warning limits stricter were obtained for aerobic mesophilic and mold populations in the different controls, except for environment of media preparation and the corresponding for sterile material. Conclusion: The process developed allowed to complement the system of internal quality control in the laboratory, to provide of an objective tool for closing nonconformities because of cross-contamination.


Rincon A.,Catholic University of Manizales | Erazo C.,National University of Colombia | Angulo F.,National University of Colombia
Journal of Process Control | Year: 2012

In this work an adaptive controller for an anaerobic digester is developed taking into account the input constraints. The following assumptions are considered: (i) the biomass and chemical oxygen demand concentrations are unknown, (ii) the model parameters are unknown and vary but they are bounded, and (iii) the upper or lower bounds of model parameters are unknown. The Lyapunov-like function method is used to derive the controller. A state observer is employed to handle the saturation of the control input, and updated parameters are used to handle the unknown bounds of the plant parameters. Some features of the control design are: (i) discontinuous signals are avoided, (ii) the boundedness of the updated parameters is ensured despite input saturation, in order to avoid parameter drifting, and (iii) the convergence of the observer error to a residual set of user-defined size is ensured despite input saturation. © 2012 Elsevier Ltd. All rights reserved.


Rincon A.,Catholic University of Manizales | Angulo F.,National University of Colombia
Journal of Process Control | Year: 2012

In this work a two-valued state feedback control is developed for a plant of second order with known constant coefficients and no disturbance, and for a plant with unknown varying coefficients and additive disturbance with known upper and lower bounds. A reference model is used in order to avoid large commutation rate of the control input. In the first part of the present work, the controller is developed by means of the Lyapunov-like function method achieving the convergence of the tracking error to a residual set whose size is user-defined. In the second part, the Lyapunov function at zero time is inside a predefined set and the developed controller forces the Lyapunov function to dwell inside such set. The size of this set is chosen such that the tracking error asymptotically converges to a residual set of user-defined size. © 2012 Elsevier Ltd. All rights reserved.

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