Papers by Mario Cantú-Sifuentes
Nova Scientia, 2015
Introduction: Service is now a key element for the economic growth of modern nations. Under a dyn... more Introduction: Service is now a key element for the economic growth of modern nations. Under a dynamic global competition environment, to increase service capabilities in the supply chains has become even more vital. For companies operating in emerging markets, the continuous upgrades in client's requests result in a challenging, continuous improvement process in service. In that context, this paper presents a comprehensive method and its informatics tool for improving performance of service supply chains, focusing on the measurement of performance of service suppliers. Method: Based on a case study in the metallurgical sector, this paper proposes a method for evaluating service suppliers, which was developed from a continuous improvement approach. This hybrid method links the application of strategic tools to a multi-criteria decision analysis to improve performance of service supply chains. Results: From a supply chain standpoint, this applied approach is helpful to academics and practitioners who evaluate complex service supplier tasks when operating in emerging markets. Discussion or Conclusion: The proposed method provides visibility and transparency related to service suppliers performance to all members of the supply chain. It delivers preventive information about supplier performance, reducing the costs of replacing suppliers with poor performance. Compared to other approaches, the main advantage of the proposed solution is the integration of quantitative and qualitative approaches to continuously improve service measurement.
Caracterización Y Aplicación De La Distribución Birnbaum-Saunders Como Modelo De Tiempos De Vida
uaaan.mx
... Saunders como Modelo de Tiempos de Vida Edgar Espinosa Cuello Mario Cantú Sifuentes Departame... more ... Saunders como Modelo de Tiempos de Vida Edgar Espinosa Cuello Mario Cantú Sifuentes Departamento de Estadística y Cálculo, Universidad Autónoma Agraria Antonio Narro, México Víctor Leiva Sánchez Departamento de Estadística, Universidad de Valparaíso, Chile. ...
A Non-Linear Model for Estimating Reliability in a Degradation Test
Material components follow non-linear degradation because the material loss with time is non-line... more Material components follow non-linear degradation because the material loss with time is non-linear; the components present different levels of resistance during a degradation process. Constructing predictions of the component life span and performing reliability analyses regarding degradation is possible by non-linear regression. In this paper, we propose new means for predicting time to failure of the components, using an extrapolation process of a calibration regression method for measuring the error prediction; an accelerated test of a polymeric coating process was performed. Results showed that the proposed model has the ability to estimate component reliability to a certain trust interval and a clear error measurement.
The International Journal of Advanced Manufacturing Technology, 2017
Maintenance has become an important support for ensuring equipment availability, on-time deliveri... more Maintenance has become an important support for ensuring equipment availability, on-time deliveries and quality of products. In that sense, reliability-centered maintenance (RCM) could be used due to its basic characteristics like costeffectiveness and accuracy. The RCM methodology is based on equipment reliability, which is estimated assuming that all failure modes are independent. However, in some cases, this assumption is not always satisfied. This paper seeks to show the effect of considering dependence for different failure modes; a comparison between traditional reliability models and copulas model is made. An injection molding process is considered for application in order to assess the proposed model and define a maintenance activities' program. Including dependence between failure modes in reliability estimation allowed 75% savings in the annual maintenance costs, which represent a direct benefit for company.
Soldagem & Inspeção, 2018
Often, welding processes used in the industry affect the mechanical properties of materials and q... more Often, welding processes used in the industry affect the mechanical properties of materials and quality of a manufactured product. There is, however, an alternative process named Friction Stir Welding (FSW), which is an solid state welding process developed to weld light alloys without compromising their mechanical properties. It is of interest to monitor the performance of FSW process to detect loss of quality. In practice, superficial and internal defects can be found; they can be identified through simple visual inspection and through visual recognition on destructive testing respectively, both procedures represent inspection by attributes. Therefore a multi-attribute control chart is assessed to monitor the process. Commonly, multi-attribute control charts involve high sampling rates to ensure accurate monitoring. In this paper, a multi-attribute control chart is proposed, considering the use of empirical control limits, instead of the theoretical ones, in order to improve its a...
ACTA ZOOLÓGICA MEXICANA (N.S.), 2011
El objetivo fue identificar las especies de trips depredadoras asociadas al cultivo del aguacate ... more El objetivo fue identificar las especies de trips depredadoras asociadas al cultivo del aguacate en el Estado de Nayarit. El trabajo se llevó a cabo en cuatro huertas de aguacate del cultivar Hass y una con los cultivares Choquette y Hall. Se realizaron muestreos semanales de enero a diciembre de 2008, utilizando las técnicas de muestreo de derribo y redeo. Se determinaron 294 trips con hábitos depredadores, resultando 16 especies. Franklinothrips vespiformis fue la especie más representada (21.8 %), seguida de Leptothrips primigenus (21.4%), y F. orizabensis (19.0 %), las restantes especies recolectadas representaron el 37.8 %.
Predator species of thrips (Thysanoptera) associated with avocado orchards in Nayarit, Mexico
Acta Zoologica Mexicana, Apr 1, 2011
A non-linear fuzzy degradation model for estimating reliability of a polymeric coating
Applied Mathematical Modelling, 2016
Abstract Oftentimes, material components follow non-linear degradation because the material loss ... more Abstract Oftentimes, material components follow non-linear degradation because the material loss trough time is non-linear; the components present different levels of resistance during a degradation process. Constructing predictions of the component life span and performing reliability analyses regarding degradation is possible by non-linear regression. Generally, this method ignores the prediction error in the extrapolated time and it does not account measurement error in the observed sample paths. In this paper, it is proposed new means for predicting time to failure of the components, using a calibration regression method for measuring the error prediction in the extrapolation process. In order to consider the uncertainty, we proposed to perform the estimated times by a trapezoidal fuzzy numbers, providing a more reliable prediction without loss of information. Since the times to failure are shaped by fuzzy numbers, it was adapted the fuzzy probability theory to the classical reliability analysis for estimating the fuzzy reliability of a component. An accelerated test of a polymeric coating process was performed and also an application for a preventive maintenance frequency was proposed.
Expert Systems with Applications, 2015
Generally, statistical methods and mathematical models are useful for process optimization. Nonet... more Generally, statistical methods and mathematical models are useful for process optimization. Nonetheless, other methods might be used for modeling and optimizing the manufacturing process. Among these, we can mention the neural networks and the Radial Basis Function technique. Hence, a suitable alternative is complementing statistical methods and neural networks as a Hybrid Learning Process. This work applies the Radial Basis Function Canonical Analysis in order to achieve the welding process optimization. One of the most important results is that the Radial Basis Function neural networks along with the Canonical Analysis are really useful methods. These methods are applied for predicting the optimal point, which establishes a reliable method for the process modeling and optimizing. The Canonical Analysis can determine stationary and saddle points, as it was in this case of study, which Canonical Analysis with RBF represented it adequately and can plot a surface and contour lines. Since in this case of study there is a surface that contains a ridge saddle system, also often called minimax. Then the results show that the Canonical Analysis can explore the region with oblique stationary and rising ridge systems. In this way, the RBF neural network with Canonical Analysis could be an alternative method for analyzing data, whenever the Hybrid Learning Process is adequate or satisfies the test assumption and fulfills the evaluation criteria. In this case of study, validation is represented by the Hybrid Learning Process (Radial Basis Function with Canonical Analysis) presenting an excellent effectiveness. As a conclusion we can say that the resulting Radial Basis Function has improved the model accuracy after using the Canonical Analysis.
Un Modelo Parámetrico De Regresión Para Datos De Tiempos De Vida Posiblemente Censurados
In research about the strength of materials, it is of interest to find probabilistic models which... more In research about the strength of materials, it is of interest to find probabilistic models which describe the behavior of the lifetime of an item as a function of an explanatory variable, for example, the temperature. However, in some cases the available data turn out to be censored. In this paper we discuss the general problem of finding a regression
Innovative Perspectives
The purpose of this document is to expose an applied methodology for improving performance of ser... more The purpose of this document is to expose an applied methodology for improving performance of service supply chains mainly focusing on performance of service suppliers running operations in emerging market context. In fact, this solution (methodology and informatics tool) was conceived as a standardized instrument for suppliers of the metallurgical sector. Whereas some researches analyze the service supplier selection, the originality of this work is its continuous improvement approach, based on a standard instrument to measure and improve the quality of service in a metallurgical supply chain. From a logistics standpoint, this applied approach was helpful to the practitioners who were faced with complex evaluating supplier tasks. Comparing with other approaches, the main advantages of the solution proposed is its hybrid methodology founded on a strong systemic point of view and, continuous improvement purpose, as well as its easiness of utilization by service suppliers themselves.
Brenesia (Costa Rica). …
RESUMEN. El presente trabajo se realizó en el Municipio de Xalisco, Nayarit, en tres huertas de a... more RESUMEN. El presente trabajo se realizó en el Municipio de Xalisco, Nayarit, en tres huertas de aguacate Hass, denominadas “La Carbonera”,“El Carrizal” y “Oreja de Ratón”. Se realizaron colectas semanales en dos periodos, octubre de 2003 a noviembre de ...
Batch Classification for Applying a Hotelling T2 Control Chart in an Automotive Process
We use the methodology proposed for Mason and Young to apply a Hotelling T2 control chart for mon... more We use the methodology proposed for Mason and Young to apply a Hotelling T2 control chart for monitoring a batch process. It assumes that the batches are well defined. However, there are highly sophisticated processes where a lot of parts are used as inputs. This makes it difficult to identify correctly the production batches. So, we propose and evaluate the Change-Point method for identifying production batches in such processes. In order to evaluate the method's effectiveness we used it in a manufacturing batch process for the automotive industry. The process parameters were estimated in two ways. One is assuming that the process is a continuos one, and the other taking into account the batches. After this the process was simulated using the two different estimations. We found that the ARL for the continuous process is lower that the ARL for batch process.
Journal of Medical Entomology, 2013
Immature blow ßies (Diptera: Calliphoridae) collected from decomposing human remains are often us... more Immature blow ßies (Diptera: Calliphoridae) collected from decomposing human remains are often used to determine the minimum postmortem interval (PMImin). Phormia regina (Meigen) is a common blow ßy of cosmopolitan distribution that is often associated in such cases. P. regina development at two different cyclic temperatures was examined in this study. A Þeld validation study was conducted to determine the accuracy of applying these data to determine the PMImin. Minimal total development time was 32.52 d at cyclic 14.0 Ϯ 2.0ЊC and 16.60 d at cyclic 20.5 Ϯ 3.1ЊC. The minimal larval development was signiÞcantly different (P Ͻ 0.05) across temperatures. Larval development needed 15.5 d at 14.0ЊC and 7.5 d at 20.5ЊC. For the validation study, instar, mean, and maximum of length and weight data of the larvae collected in the Þeld were analyzed with data generated from the 20.5ЊC treatment, as it more closely reßected the Þeld conditions experienced. Accuracy in estimating PMImin, was highly variable depending on the unit of measurement used and instar of P. regina collected from the Þeld. Using the oldest instar to estimate a PMImin resulted in ranges that always encompassed the true time of colonization. Accuracy in hours when using measurements units as mean length or weight, and maximal length or weight, varied among the larval instars. In the Þrst instar the greatest overestimation was made with maximal weight while the greatest underestimation was made with mean weight. The most accurate estimate produced with Þrst instars was based on maximal length. In the second instar, there was no overestimation and the greatest underestimation was made with mean weight and the most accurate estimate produced was with maximal length. In the third instar, the greatest overestimation was made with maximal length, and the greatest underestimation was made with mean weight. The estimated time of colonization based on maximal weight was most accurate for third instars.
Fuzzy reliability analysis with only censored data
Engineering Applications of Artificial Intelligence, 2014
ABSTRACT It is expected that samples in reliability analysis contain both censored and complete f... more ABSTRACT It is expected that samples in reliability analysis contain both censored and complete failure data; thus, the maximum likelihood method is used to estimate the parameters of the related distribution. Nonetheless, samples may contain only censored data; therefore introducing a high degree of uncertainty which does result in non-viability for either the likelihood method or for statistical inference. This paper proposes the use of fuzzy probability theory to account for the uncertainty and the prior knowledge of the process in the parameters׳ estimation, for censored data. The proposed method was applied to risk based inspection. Results demonstrate that our method represents a reliable option for using the expert knowledge about the component and the physics of the failure mode. Additionally, an inspection time was estimated based on target risk; the results confirm that the methodology could be used to develop maintenance plans.
Engineering Applications of Artificial Intelligence, 2013
A Hybrid Learning Process method was fitted into a RBF. The resulting redesigned RBF intends to s... more A Hybrid Learning Process method was fitted into a RBF. The resulting redesigned RBF intends to show how to test if the statistical assumptions are fulfilled and to apply statistical inference to the redesigned RBFNN bearing in mind that it allows to determine the relationship between a response (to a process) and one or more independent variables, testing how much each factor contributes to the total variation of the response is also feasible. The results show that statistical methods such as inference, Residual Analysis, and statistical metrics are all good alternatives and excellent methods for validation of the effectiveness of the Neural Network models. The foremost conclusion is that the resulting redesigned Radial Basis Function improved the accuracy of the model after using a Hybrid Learning Process; moreover, the new model also validates the statistical assumptions for using statistical inference and statistical analysis, satisfying the assumptions required for ANOVA to determine the statistical significance and the relationship between variables.
Terra …, 2010
Modelo para estimar un límite superior de laborabilidad del suelo en función de su textura y conc... more Modelo para estimar un límite superior de laborabilidad del suelo en función de su textura y concentración de materia orgánica
A non-linear fuzzy regression for estimating reliability in a degradation process
Applied Soft Computing, 2014
Since some assumptions such as the function @f(.) needs to be completely specified and the relati... more Since some assumptions such as the function @f(.) needs to be completely specified and the relationship between @m and @f(s) must have linear behavior in the model @[email protected](S) used in the accelerated life testing analysis, generally do not hold; the estimation of stress level contains uncertainty. In this paper, we propose to use a non-linear fuzzy regression model for performing the extrapolation process and adapting the fuzzy probability theory to the classical reliability including uncertainty and process experience for obtaining fuzzy reliability of a component. Results show, that the proposed model has the ability to estimate reliability when the mentioned assumptions are violated and uncertainty is implicit; so that the classical models are unreliable.
A PARAMETRIC REGRESSION MODEL FOR POSSIBLY CENSORED LIFETIME DATA Agrociencia, Julio-Agosto, año/Vol. 34, Número 004 Colegio De …
…, 2000
Agrociencia. Colegio de Postgraduados. [email protected]. ISSN (Versión impresa): 1405-31... more Agrociencia. Colegio de Postgraduados. [email protected]. ISSN (Versión impresa): 1405-3195. MÉXICO. 2000. Mario Cantú Sifuentes / José A. Villaseñor Alva / Barry C. Arnold. A PARAMETRIC REGRESSION MODEL ...
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Papers by Mario Cantú-Sifuentes