Relación entre prevalencia de caries dental en niños entre 6 y 12 años de edad y el nivel de conocimiento de sus madres en salud oral en la unidad educativa Sigsillano 2015-2016

Tesis (Magíster en Salud Pública)Para determinar la relación entre la prevalencia de caries dental en escolares de entre 6 y 12 años de edad y el nivel de conocimiento de sus madres en salud oral en la Unidad Educativa Sigsillano 2015-2016, se estudió una muestra de 113 niños/as con sus respectivas madres de familia. A los niños/as se les realizó un examen clínico buco dental para determinar la prevalencia de caries dental por medio de los índices CPOD y ceod y a las madres se les aplicó una encuesta para establecer el nivel de conocimiento en salud oral. El estudio reveló que existe, relación estadísticamente significativa de p= 0,000 entre la frecuencia de caries dental en escolares y nivel de conocimiento de sus madres en salud oral. La frecuencia de caries dental de los niños/as es de 92,9 %, así mismo el nivel de frecuencia de caries dental obtenido mediante el índice CPOD es bajo (32,7%), medio (34,5%) y alto (32,7%). El nivel de conocimiento sobre salud oral de las madres encuestadas fue de nivel alto en un 32,7% y el 67,3 % en nivel entre medio (43,4%), y bajo (23,9%)

Monitoring of an aquatic environment in aquaculture using a MEWMA chart

Systematic reproduction and distribution, duplication of any material in this paper for a fee or for commercial purposes, or modifications of the content of this paper are prohibited.[EN] Monitoring an aquatic environment in aquaculture is usually carried out by controlling its physicochemical and biological parameters. The global state of the process is evaluated though the individual conditions shown in each parameter. However, the correlation structure in the data, caused by interdependence between these parameters, provides relevant information which must be controlled. Thus, the complex structure of the data requires a multivariate control method to explore both the individual and interactive effects of the environmental parameters. To achieve this goal, this paper presents a statistical method based on a Multivariate Exponentially Moving Average (MEWMA) chart to monitor the multivariate structure of an aquatic environment in aquaculture, especially in a crop of tilapia in Mozambique. The results show that the adjusted MEWMA chart is more consistent when controlling the conformity and stability of environmental parameters. Therefore, it can be considered an efficient statistical method to monitor an aquatic environment in aquaculture.Mulema, SA.; Carrión García, A. (2019). Monitoring of an aquatic environment in aquaculture using a MEWMA chart. Aquaculture. 504:275-280. https://doi.org/10.1016/j.aquaculture.2019.01.019S27528050

Quality and productivity in aquaculture: Prediction of oreochromis mossambicus growth using a transfer function ARIMA model

[EN] The cultivation of aquatic species in aquaculture aims at improving fish production, making the activity more dependent on human capacity, especially with what concerns to the application of efficient methods for its management. The weight and standard length are the biometric parameters mostly used to control the growth of tilapia in the cultivation process. In this work there is presented a statistical method based on transfer function ARIMA model to adjust and predict the weight of tilapia with the support of the values of the standard length. The model was adjusted to the data recorded in 21 weeks in the tilapia growing tank of the company Aquapesca de Mocambique, and the results showed that there was a good adjustment (with an explained variability of 97.8%) with which the model can be used to predict the future values of tilapia weight and make the activity more controllable and profitable.I would like to thank the Universidade Pedagógica de Moçambique, Delegação de Quelimane for funding this research and the the company Aquapesca de Moçambique for guaranteeing the experimental phase of this work.Mulema, SA.; Carrión García, A. (2018). Quality and productivity in aquaculture: Prediction of oreochromis mossambicus growth using a transfer function ARIMA model. International Journal for Quality Research. 12(4):823-834. https://doi.org/10.18421/IJOR12.04-03S82383412

A heuristic method for obtaining quasi ARL-unbiased p-Charts

[EN] It is known that control charts based on equal tail probability limits are ARL biased when the distribution of the plotted statistic is skewed. This is the case for p¿Charts that serve to monitor processes on the basis of the binomial distribution. For the particular case of the standard three¿sigma Shewhart p¿Chart, which is built on the basis of the binomial to normal distribution approximation, this ARL¿biased condition is particularly severe, and it greatly affects its monitoring capability. Surprisingly, in spite of this, the standard p¿Chart is still widely used and taught. Through a literature search, it was identified that several, simple to use, improved alternative p¿Charts had been proposed over the years; however, at first instance, it was not possible to determine which of them was the best. In order to identify the alternative that excelled, an ARL performance comparison was carried out in terms of their ARL bias severity level (ARLBSL) and their In¿Control ARL (ARL0). The results showed that even the best performing alternative charts would often be ARL¿biased or have nonoptimal ARL0. To improve on the existing alternatives, the ¿Kmod p¿Chart¿ was developed; it offers easiness of use, superior ARL performance, and a simple and effective method for verifying its ARL¿bias condition.Argoti, MA.; Carrión García, A. (2019). A heuristic method for obtaining quasi ARL-unbiased p-Charts. Quality and Reliability Engineering International. 35(1):47-61. https://doi.org/10.1002/qre.2379S476135

New approaches to parameter estimation with statistical censoring by means of the CEV algorithm: Characterization of its properties for high-performance normal processes

[EN] The process of parameter estimation in order to characterize a population using algorithms is in constant development and perfection. Recent years show that data-based decision-making is complex when there is uncertainty generated by statistical censoring. The purpose of this article is to evaluate the effect of statistical censoring on the normal distribution, which is common in many processes. Parameter estimation properties will be characterized with the conditional expected value algorithm, using different censoring percentages and sample sizes. The estimation properties chosen for the study will focus on the monitoring and decision-making related to industrial processes with the presence of censoring.Neira Rueda, J.; Carrión García, A. (2023). New approaches to parameter estimation with statistical censoring by means of the CEV algorithm: Characterization of its properties for high-performance normal processes. Communication in Statistics- Theory and Methods. 52(10):3557-3573. https://doi.org/10.1080/03610926.2021.197732335573573521

Análisis de técnicas de estimulación para minimizar y remediar los daños de formación por migración de finos en el reservorio hollín, del campo Palo Azul

Tesis basada en el análisis de técnicas de estimulación para minimizar y remediar los daños de formación por migración de finos en el reservorio hollín, con la selección de la técnica de estimulación más adecuada, para optimizar la producción de petróleo. OBJETIVO: Optimizar la producción de los pozos en el Reservorio Hollín del Campo Palo Azul, con la aplicación de técnicas de estimulación para minimizar y remediar daños de formación por migración de finos. PROBLEMA: El estudio de técnicas de estimulación ya existentes en la industria petrolera para evitar el daño de formación provocada por migración de finos en los pozos de estudio del Campo “Palo Azul”, serán de gran importancia para optimizar la producción de petróleo y que las operaciones sean técnica y económicamente rentables. MARCO TEÓRICO: Descripción general del Campo “PALO AZUL”, propiedades petrofísicas, propiedades de los fluidos, análisis histórico de los pozos en estudio con daño de formación, análisis y selección de la mejor técnica para reducir el daño de formación, tipo de levantamiento artificial utilizado en el campo “Palo Azul”, diseño y planificación de la estimulación a utilizarse en los pozos candidatos.Thesis based on analysis of stimulation techniques aimed at minimized and remedying formation damages caused by the migration of fine particles into the soot reservoir, and the selection of the most adequate stimulation technique in order to optimize oil production. GOAL: Optimize the production of oil wells in the Soot Reservoir of “Palo Azul” Field, with the use of stimulation techniques aimed at minimizing and remedying formation damages caused by the migration of fine particles. ISSUE: The study of existing stimulation techniques in the oil industry to avoid the damage to the formation caused by the migration of fine particles in the studied wells of “Palo Azul” field will have great importance in optimizing oil production and making operations more technical and economically viable. THEORETICAL FRAMEWORK : General description of “Palo Azul” field, petrophysical properties, fluids properties, historical analysis of wells with formation damage under study, analysis and selection of the best technique to reduce the formation damage, type of artificial mapping used in the field, design and planning of stimulation to be conducted in the chosen wells

La abuela en la vitrina: Elementos del diseño de la muestra etnográfica y su tejido discursivo en la representación de las minorías étnicas.

En este trabajo se realiza una revisión de las características de diseño que componen la muestra etnográfica del museo Nacional Pumapungo, en la ciudad de Cuenca, haciendo una categorización de componentes que permitan dilucidar el tejido discursivo con el que dicho museo interpreta la identidad de las minorías étnicas del Ecuador

Characterisation and optimal design of a new double sampling c chart

[EN] This paper proposes a new double sampling scheme for c control chart (DS-c), which was designed to improve the performance of c chart or to reduce the inspection cost. The mathematical expression required to do an exact evaluation of ARL and ASN is deduced. Further, a bi-objective genetic algorithm is implemented to obtain the optimal design of the DS-c scheme. This optimisation is aimed to simultaneously minimising the error probability type II and the ASN, guaranteeing a desired level for the error probability type I. A performance comparison between the double sampling (DS), fixed parameters (FP), variable simple size (VSS) and exponential weighted moving average (EWMA) schemes for the c chart is carried out. The comparison shows that with the implementation of DS-c scheme is obtained a significant reduction of the out of control ARL with a lower ASN respect to FP and a better ARL profile than VSS and EWMA.Campuzano, MJ.; Carrión García, A.; Mosquera, J. (2019). Characterisation and optimal design of a new double sampling c chart. European J of Industrial Engineering. 13(6):775-793. https://doi.org/10.1504/EJIE.2019.104312S77579313

The impact of measurement systems performance on process capability evaluation

[EN] The evaluation of quality of products and processes depends on the ability to obtain accurate measurements consistently over time. With these measurements different control tools are used to monitor the performance of processes and the conformity of products. One of these tools, widely used and each time more recognized as relevant, is Capability analysis. Through a set of wellknown parameters, as Cp and Cpk, capability is a key element in quality control with a continuous improvement approach. As capability indexes are computed using data coming from measurement processes, the consistency of capability indexes depends highly in the quality and reliability of the measurements obtained from such processes. In this paper we analyze the relation between the performance of the measurement systems and the representativity of the capability studies.Carrión García, A.; Grisales Del Rio, AM. (2020). The impact of measurement systems performance on process capability evaluation. DQM Research Center. 55-65. https://doi.org/10.6084/m9.figshare.13317617S556