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

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

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

Further Results on the Total Roman Domination in Graphs

[EN] Let G be a graph without isolated vertices. A function f:V(G)-> {0,1,2} is a total Roman dominating function on G if every vertex v is an element of V(G) for which f(v)=0 is adjacent to at least one vertex u is an element of V(G) such that f(u)=2 , and if the subgraph induced by the set {v is an element of V(G):f(v)>= 1} has no isolated vertices. The total Roman domination number of G, denoted gamma tR(G) , is the minimum weight omega (f)=Sigma v is an element of V(G)f(v) among all total Roman dominating functions f on G. In this article we obtain new tight lower and upper bounds for gamma tR(G) which improve the well-known bounds 2 gamma (G)<= gamma tR(G)<= 3 gamma (G) , where gamma (G) represents the classical domination number. In addition, we characterize the graphs that achieve equality in the previous lower bound and we give necessary conditions for the graphs which satisfy the equality in the upper bound above.Cabrera Martínez, A.; Cabrera García, S.; Carrión García, A. (2020). Further Results on the Total Roman Domination in Graphs. Mathematics. 8(3):1-8. https://doi.org/10.3390/math8030349S1883Henning, M. A. (2009). A survey of selected recent results on total domination in graphs. Discrete Mathematics, 309(1), 32-63. doi:10.1016/j.disc.2007.12.044Henning, M. A., & Yeo, A. (2013). Total Domination in Graphs. Springer Monographs in Mathematics. doi:10.1007/978-1-4614-6525-6Henning, M. A., & Marcon, A. J. (2016). Semitotal Domination in Claw-Free Cubic Graphs. Annals of Combinatorics, 20(4), 799-813. doi:10.1007/s00026-016-0331-zHenning, M. . A., & Marcon, A. J. (2016). Vertices contained in all or in no minimum semitotal dominating set of a tree. Discussiones Mathematicae Graph Theory, 36(1), 71. doi:10.7151/dmgt.1844Henning, M. A., & Pandey, A. (2019). Algorithmic aspects of semitotal domination in graphs. Theoretical Computer Science, 766, 46-57. doi:10.1016/j.tcs.2018.09.019Cockayne, E. J., Dreyer, P. A., Hedetniemi, S. M., & Hedetniemi, S. T. (2004). Roman domination in graphs. Discrete Mathematics, 278(1-3), 11-22. doi:10.1016/j.disc.2003.06.004Stewart, I. (1999). Defend the Roman Empire! Scientific American, 281(6), 136-138. doi:10.1038/scientificamerican1299-136Chambers, E. W., Kinnersley, B., Prince, N., & West, D. B. (2009). Extremal Problems for Roman Domination. SIAM Journal on Discrete Mathematics, 23(3), 1575-1586. doi:10.1137/070699688Favaron, O., Karami, H., Khoeilar, R., & Sheikholeslami, S. M. (2009). On the Roman domination number of a graph. Discrete Mathematics, 309(10), 3447-3451. doi:10.1016/j.disc.2008.09.043Liu, C.-H., & Chang, G. J. (2012). Upper bounds on Roman domination numbers of graphs. Discrete Mathematics, 312(7), 1386-1391. doi:10.1016/j.disc.2011.12.021González, Y., & Rodríguez-Velázquez, J. (2013). Roman domination in Cartesian product graphs and strong product graphs. Applicable Analysis and Discrete Mathematics, 7(2), 262-274. doi:10.2298/aadm130813017gLiu, C.-H., & Chang, G. J. (2012). Roman domination on strongly chordal graphs. Journal of Combinatorial Optimization, 26(3), 608-619. doi:10.1007/s10878-012-9482-yAhangar Abdollahzadeh, H., Henning, M., Samodivkin, V., & Yero, I. (2016). Total Roman domination in graphs. Applicable Analysis and Discrete Mathematics, 10(2), 501-517. doi:10.2298/aadm160802017aAmjadi, J., Sheikholeslami, S. M., & Soroudi, M. (2019). On the total Roman domination in trees. Discussiones Mathematicae Graph Theory, 39(2), 519. doi:10.7151/dmgt.2099Cabrera Martínez, A., Montejano, L. P., & Rodríguez-Velázquez, J. A. (2019). Total Weak Roman Domination in Graphs. Symmetry, 11(6), 831. doi:10.3390/sym1106083

Propuesta para la creación de un plan de mantenimiento basado en el análisis modal de falla y efecto (AMEF- AMFE), aplicable a empresas de impresión y artes gráficas

74 p

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

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

Forest-Genetic method to optimize parameter design of multiresponse experiment

[EN] We propose a methodology for the improvement of the parameter design that consists of the combination of Random Forest (RF) with Genetic Algorithms (GA) in 3 phases: normalization, modelling and optimization. The first phase corresponds to the previous preparation of the data set by using normalization functions. In the second phase, we designed a modelling scheme adjusted to multiple quality characteristics and we have called it Multivariate Random Forest (MRF) for the determination of the objective function. Finally, in the third phase, we obtained the optimal combination of parameter levels with the integration of properties of our modelling scheme and desirability functions in the establishment of the corresponding GA. Two illustrative cases allow us to compare and validate the virtues of our methodology versus other proposals involving Artificial Neural Networks (ANN) and Simulated Annealing (SA).[ES] Proponemos una metodología para la mejora del diseño de parámetros que consiste en la combinación de Random Forest (RF) con Algoritmos Genéticos (GA) en 3 fases: normalización, modelización y optimización. La primera fase corresponde a la preparación previa del conjunto de datos mediante funciones de normalización. En la segunda fase, diseñamos un esquema de modelización ajustado a múltiples características de calidad, que hemos llamado Multivariante Random Forest (MRF) para la determinación de la función objetivo. Finalmente, en la tercera fase se obtiene la combinación ¿optima de los niveles de los parámetros mediante la integración de propiedades dadas por nuestro esquema de modelización y las desirabibity functions en el establecimiento del correspondiente GA. Dos casos ilustrativos nos permiten comparar y validar las virtudes de nuestra metodología versus otras propuestas que involucran Redes Neuronales Artificiales (ANN) y Simulated Annealing (SA).Villa Murillo, A.; Carrión García, A.; Sozzi, A. (2020). Forest-Genetic method to optimize parameter design of multiresponse experiment. Inteligencia Artificial. Revista Iberoamericana de Inteligencia Artificial. 23(66):9-25. https://doi.org/10.4114/intartif.vol23iss66pp9-25S925236

Relevance of Skills in Total Quality Management in Engineering Studies as a Tool for Performing Their Jobs

[EN] The Spanish higher education system needs to adapt to the requirements of the European Higher Education Area and to this end, it is necessary for higher education institutions to improve the quality of university education, leading to an increase in competency-based learning activities aimed at developing the skills of graduates. Since university graduates face a large number of requirements when entering the labour market, they need to develop and constantly update the appropriate skills to carry out their work properly. This paper aims to address two fundamental questions. First, do engineering graduates need acquired skills in Total Quality Management (TQM) to perform their jobs successfully? Secondly, which job profile requires the highest level of Total Quality Management training and knowledge? We carried out different multivariate statistical analyses using a sample of engineering graduates who had been in the labour market for two years. The results show that knowledge of this type of management philosophy is necessary for adequate job performance. The job profile requiring the highest level of skills in TQM is described.Martínez-Gómez, M.; Jabaloyes Vivas, JM.; Carrión García, A. (2020). Relevance of Skills in Total Quality Management in Engineering Studies as a Tool for Performing Their Jobs. Sustainability. 12(5):1-15. https://doi.org/10.3390/su12052065S115125Kanji, G. K., Malek, A., & Tambi, B. A. (1999). Total quality management in UK higher education institutions. Total Quality Management, 10(1), 129-153. doi:10.1080/0954412998126Heijke, H., Meng, C., & Ramaekers, G. (2003). An investigation into the role of human capital competences and their pay‐off. International Journal of Manpower, 24(7), 750-773. doi:10.1108/01437720310502113Jaca, C., & Psomas, E. (2015). Total quality management practices and performance outcomes in Spanish service companies. Total Quality Management & Business Excellence, 26(9-10), 958-970. doi:10.1080/14783363.2015.1068588Chen, R., Lee, Y.-D., & Wang, C.-H. (2018). Total quality management and sustainable competitive advantage: serial mediation of transformational leadership and executive ability. Total Quality Management & Business Excellence, 31(5-6), 451-468. doi:10.1080/14783363.2018.1476132Weil, S. (1999). Re-creating universities for ‘beyond the stable state’: from ‘Dearingesque’ systematic control to post-Dearing systemic learning and inquiry. Systems Research and Behavioral Science, 16(2), 171-190. doi:10.1002/(sici)1099-1743(199903/04)16:23.0.co;2-aSleezer, C. M., Gularte, M. A., Waldner, L., & Cook, J. (2008). Business and Higher Education Partner to Develop a High-Skilled Workforce: A Case Study. Performance Improvement Quarterly, 17(2), 65-81. doi:10.1111/j.1937-8327.2004.tb00308.xPossa, G. (2006). Europe’s Universities in Response to Europe’s Challenges. Higher Education in Europe, 31(4), 355-357. doi:10.1080/03797720701302907Andrews, J., & Higson, H. (2008). Graduate Employability, ‘Soft Skills’ Versus ‘Hard’ Business Knowledge: A European Study. Higher Education in Europe, 33(4), 411-422. doi:10.1080/03797720802522627Yusof, S. M., & Aspinwall, E. (2000). Total quality management implementation frameworks: Comparison and review. Total Quality Management, 11(3), 281-294. doi:10.1080/0954412006801Dean, J. W., & Bowen, D. E. (1994). MANAGEMENT THEORY AND TOTAL QUALITY: IMPROVING RESEARCH AND PRACTICE THROUGH THEORY DEVELOPMENT. Academy of Management Review, 19(3), 392-418. doi:10.5465/amr.1994.9412271803Hellsten, U., & Klefsjö, B. (2000). TQM as a management system consisting of values, techniques and tools. The TQM Magazine, 12(4), 238-244. doi:10.1108/09544780010325822Curry, A., & Kadasah, N. (2002). Focusing on key elements of TQM – evaluation for sustainability. The TQM Magazine, 14(4), 207-216. doi:10.1108/09544780210429816Hackman, J. R., & Wageman, R. (1995). Total Quality Management: Empirical, Conceptual, and Practical Issues. Administrative Science Quarterly, 40(2), 309. doi:10.2307/2393640Singh, P. J., & Smith, A. J. R. (2004). Relationship between TQM and innovation: an empirical study. Journal of Manufacturing Technology Management, 15(5), 394-401. doi:10.1108/17410380410540381Asif, M., Searcy, C., Garvare, R., & Ahmad, N. (2011). Including sustainability in business excellence models. Total Quality Management & Business Excellence, 22(7), 773-786. doi:10.1080/14783363.2011.585784Rocha-Lona, L., Garza-Reyes, J. A., Lim, M. K., & Kumar, V. (2015). Corporate Sustainability and Business Excellence. 2015 International Conference on Industrial Engineering and Operations Management (IEOM). doi:10.1109/ieom.2015.7093844Zink, K. J. (2007). From total quality management to corporate sustainability based on a stakeholder management. Journal of Management History, 13(4), 394-401. doi:10.1108/17511340710819615Lagrosen, Y., & Lagrosen, S. (2019). Creating a culture for sustainability and quality – a lean-inspired way of working. Total Quality Management & Business Excellence, 1-15. doi:10.1080/14783363.2019.1575199Motwani, J. (2001). Critical factors and performance measures of TQM. The TQM Magazine, 13(4), 292-300. doi:10.1108/13683040010362300Rahman, S. (2001). A comparative study of TQM practice and organisational performance of SMEs with and without ISO 9000 certification. International Journal of Quality & Reliability Management, 18(1), 35-49. doi:10.1108/02656710110364486Petroni, A. (2002). Critical factors of MRP implementation in small and medium‐sized firms. International Journal of Operations & Production Management, 22(3), 329-348. doi:10.1108/01443570210417623Brah, S. A., & Ying Lim, H. (2006). The effects of technology and TQM on the performance of logistics companies. International Journal of Physical Distribution & Logistics Management, 36(3), 192-209. doi:10.1108/09600030610661796Hervás Jorge, A., Ayats, J. C., Desantes, R., & Juliá, J. F. (2012). Las prácticas en empresa como uno de los ejes vertebradores de la empleabilidad. Revista Iberoamericana de Educación Superior. doi:10.22201/iisue.20072872e.2012.8.70Kass, G. V. (1980). An Exploratory Technique for Investigating Large Quantities of Categorical Data. Applied Statistics, 29(2), 119. doi:10.2307/2986296Kaiser, H. F. (1958). The varimax criterion for analytic rotation in factor analysis. Psychometrika, 23(3), 187-200. doi:10.1007/bf0228923