Browsing by Author "Ospina-Mateus H."

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An EPQ inventory model considering an imperfect production system with probabilistic demand and collaborative approach
(Emerald Group Publishing Ltd., 2019) Salas-Navarro K.; Acevedo Chedid, Jaime; Árquez G.M.; Florez W.F.; Ospina-Mateus H.; Sana S.S.; Cárdenas-Barrón L.E.
Purpose: The purpose of this paper is to propose an economic production quantity (EPQ) inventory model considering imperfect items and probabilistic demand for a two-echelon supply chain. The production process is imperfect and the imperfect quality items are removed from the lot size. The demand rate of the inventory system is random and follows an exponential probability density function and the demand of the retailers is depending on the initiatives of the sales team. Design/methodology/approach: Two approaches are examined. In the non-collaborative approach, any member of the supply chain can be the leader and takes decisions to optimize the profits, and in the collaborative system, all members make joint decisions about the production, supply, sales and inventory to optimize the profits of the supply chain members. The calculus approach is applied to find the maximum profit related to the members of the supply chain. Findings: A numerical example is presented to illustrate the performance of the EPQ model. The results show that collaborative approach generates greater profits to the supply chain and the market’s demand represents the variable behavior and uncertainty that is generated in the replenishment of a supply chain. Originality/value: The new and major contributions of this research are: the inventory model considers demand for products is random variable which follows an exponential probability distribution function and it also depends on the initiatives of sales teams, the imperfect production system generates defective items, different cycle time are considered in manufacturer and retailers and collaborative and non-collaborative approaches are also studied. © 2019, Emerald Publishing Limited.
Application of genetic algorithm to job scheduling under ergonomic constraints in manufacturing industry
(Springer Verlag, 2019) Sana S.S.; Ospina-Mateus H.; Arrieta F.G.; Chedid J.A.
This research proposes a mathematical model of the problem of job rotation considering ergonomic aspects in repetitive works, lifting tasks and awkward postures in manufacturing environments with high variability. The mathematical model is formulated as a multi-objective optimization problem integrating the ergonomic constraints and is solved using improved non-dominated sorting genetic algorithm. The proposed algorithm allows the generation of diversified results and a greater search convergence on the Pareto front. The algorithm avoids the loss of convergence in each border by means of change and replacement of similar solutions. In this strategy, a single similar result is preserved and the best solution of the previous generation is included. If the outcomes are similar, new randomly generated individuals are proposed to encourage diversity. The obtained results improve the conditions of 69% of the workers. The results show that if the worker rotates starting from a high risk, his variation in risk always decreases in his next assignment. Within the job rotation scheme, no worker is exposed simultaneously to high ergonomic risk thresholds. The model and the algorithm provide good results while considering ergonomic risks. The proposed algorithm shows the potentiality to generate a set of quality of response (Pareto Frontier) in a combinatorial optimization problem in an efficient computational time. © 2018, Springer-Verlag GmbH Germany, part of Springer Nature.
Bibliometric analysis in motorcycle accident research: a global overview
(Springer Netherlands, 2019) Ospina-Mateus H.; Quintana Jiménez, Leonardo Augusto; López Valdés, Francisco J.; Salas-Navarro K.
770 million motorcycles are estimated on the roads. Motorcyclists represent more than 380,000 annual deaths worldwide. 28% of the global fatalities in the roads in 2016. With the increase of the accident rate, studies have been developed within the scientific literature. Bibliometric analysis is applied in the field of motorcycle safety in order to identify relevant publications on risk factors of road crashes and their implications. The information in this research was extracted from Web of Science and Scopus databases between 1947 and May 31, 2018. The study identified the key bibliometric indicators such as publications, authors, journals, countries, institutions, citation and co-citation analysis, subject categories, and co-occurrence of terms. EndNote, Microsoft Excel, Statgraphics Centurion and VOS-viewer software were used for the analysis. In total, 1813 articles were considered. The publications from 2000 to 2017 exhibits an average growth of 9%. The journal “Accident Analysis and Prevention” was the key issue in the publication and citation. The top institutions were the University of California, Universiti Putra Malaysia, and Monash University. The average citation of the top 10 articles was 134. A network visualization map showed that ‘vehicle’, ‘model’, ‘system’, ‘road’, ‘safety’, and ‘behavior’ were the most commons key terms. Bibliometric analysis demonstrates a high collaboration between authors and institutions. Two growing trends were identified. First, studies on the protection of the motorcyclist and the safe design considering the performance. Second, studies in analysis, characterization, and prevention of accidents. These studies are more related to the generation of strategies for the protection of road safety for motorcyclists. © 2019, Akadémiai Kiadó, Budapest, Hungary.
Ergonomic and biomechanical evaluation of the use of computers, tablets and smart phones by children. A pilot study
(Springer Verlag, 2017) Ospina-Mateus H.; Niño-Prada B.; Tilbe Ayola, Keyla Rosa; Contreras Ortiz, Sonia Helena; Bustamante J.; Sierra D.A.; Torres I.
The use of technological devices has widespread around the world. It is known that inappropriate or prolonged use of electronic devices can cause musculoskeletal discomfort or even illness. However, there are not many studies that evaluate the associated risks on the children’s health. This paper describes a pilot ergonomic study for the analysis of the postures of a five-year old girl while using a laptop computer, a tablet, and a smart phone. The analysis was done using the software Delmia to generate 3D models of the child body, that were created based on photographs. We considered five positions: desk sitting, sitting cross legged, lying supine, lying prone and standing. The results suggest that the safest positions are sitting on a desk and standing, and the greatest risk is in the area of necktrunk. However, further investigation is needed to validate the musculoskeletal risks associated to the use of electronic devices by children. © Springer Nature Singapore Pte Ltd. 2017.
Implementation of an E.R.P. Inventory Module in a Small Colombian Metalworking Company
(Springer, 2020) Coronado Hernández, Jairo Rafael; Ospina-Mateus H.; Canabal-Gónzalez D.; Peña-Ballestas D.; Baron-Villamizar, Javier; Mercado-Carusso N.; Romero-Conrado A.R.; Paternina-Arboleda C.; Silva J.
This paper aims to analyze the effect of implementing an inventory module of ERP Openbravo for the reduction of information flow time and customer response time, in a Colombian metalworking company. The processes structure and inventory management practices of the company were characterized and information flow time and customer response time were tested before and after implementing the inventory module. The main results were the reduction of 36% of information flow time and 41% of customer response time, so it can be concluded that obtained success is related to the active involvement of manager and workers’ willingness to change. © Springer Nature Switzerland AG 2020.
Model of optimization of mining complex for the planning of flow of quarry production of limestone in multiple products and with elements for the analysis of the capacity
(Springer Verlag, 2017) Ospina-Mateus H.; Acevedo Chedid, Jaime; Salas-Navarro K.; Morales-Londoño N.; Montero-Perez J.; Figueroa-Garcia J.C.; Lopez-Santana E.R.; Ferro-Escobar R.; Villa Ramírez, José Luis
Activities in mining complexes contain multiple decisions that affect the operations of the system for the extraction, transformation, transport and storage of various subsoil components. The purpose of this research is the planning of continuous flow production systems for mixed products, in non-metallic mining extraction processes, considering bottlenecks and capacity planning. This paper presents a model for production, based on mathematical optimization, that facilitates the planning and management of operations in the area of extraction, crushing and transformation of a quarry of aggregates for construction, considering the resources and the constraints that allow to define effective strategies in the increase of the productivity of the lines of low production environment by scenarios. This research develops an analysis of bottlenecks and contrasts the nature of the production system by means of a mathematical model of optimization, which considers the capacities and balances in the flows of the Limestone production line. The mathematical model that maximizes profits can be adapted to systems of continuous flow production in mining complexes where their products are part of a reverse logistics process, analysis of alternatives of extraction, transformation and transport. © 2017, Springer International Publishing AG.
Reactive scheduling in collaborative supply chain: A literature review
(Revista Espacios, 2017) Acevedo Chedid, Jaime; Salas-Navarro K.; Ospina-Mateus H.; Santander-Mercado A.
This paper aims to review the literature on the reprogramming of production in collaborative supply chains, through a thorough investigation and Scientometric analysis to identify the behavior of publications in recent years, which allow the identification of authors, areas Of the knowledge, countries and institutions most unrelated in the area. Finally, research lines are presented with a greater tendency for new research that contributes to the literature and the improvement of stocks. © 2017.
Understanding the impact of physical fatigue and postural comfort experienced during motorcycling: A systematic review
(Elsevier Ltd, 2019) Ospina-Mateus H.; Quintana Jiménez, Leonardo Augusto
Background: This literature review examines reports on the effects of fatigue and comfort on the motorcycle driving experience and evaluates studies of associated relevant risk factors for musculoskeletal disorders. Methods: This systematic review of literature employed a synthetic approach using best evidence to address the question: “Does fatigue and postural comfort contribute to the development of musculoskeletal conditions and disorders presented by motorcyclists?” The initial search identified 9,024 academic articles published from 1970 to date, in 13 databases. After screening, a total of 35 articles met the criteria and were included. twelve were found to be of high quality, eighteen of medium quality, and five of low quality. Results: In this systematic review, postural and anthropometric factors, as well as techniques and tools for the muscular analysis of motorcyclists were identified. The tools identified were classified into direct assessment techniques (anthropometry, electromyography, dynamometry, vibration evaluation, seat pressure analysis, heart rate and blood pressure, and fatigue of the pupillary muscles) and observational or indirect assessment techniques (self-reports and questionnaires). Most of the reviewed studies (83%) included evidence that physical fatigue and postural discomfort affect the performance and are related to musculoskeletal conditions; 17% (six) of the studies evaluated provided neutral evidence. The lower back was the area of the body most affected by discomfort and fatigue in motorcyclists (63% of the studies), followed by the shoulder and forearm (51% of studies). Other affected areas were the neck, and the buttocks reported by 34 to 43% of the included studies. Conclusion: Our review shows that the different muscles affected due to motorcycle driving and the techniques used for assessment need to be comprehensively evaluated. Thus, proper selection and design of motorcycles is imperative for improving the comfort of motorcyclists. © 2019 Elsevier Ltd
Using Data-Mining Techniques for the Prediction of the Severity of Road Crashes in Cartagena, Colombia
(Springer, 2019) Ospina-Mateus H.; Quintana Jiménez, Leonardo Augusto; López-Valdés F.J.; Morales-Londoño N.; Salas-Navarro K.; Figueroa-Garcia J.C.; Duarte-Gonzalez M.; Jaramillo-Isaza S.; Orjuela-Canon A.D.; Diaz-Gutierrez Y.
Objective: Analyze the road crashes in Cartagena (Colombia) and the factors associated with the collision and severity. The aim is to establish a set of rules for defining countermeasures to improve road safety. Methods: Data mining and machine learning techniques were used in 7894 traffic accidents from 2016 to 2017. The severity was determined between low (84%) and high (16%). Five classification algorithms to predict the accident severity were applied with WEKA Software (Waikato Environment for Knowledge Analysis). Including Decision Tree (DT-J48), Rule Induction (PART), Support Vector Machines (SVMs), Naïve Bayes (NB), and Multilayer Perceptron (MLP). The effectiveness of each algorithm was implemented using cross-validation with 10-fold. Decision rules were defined from the results of the different methods. Results: The methods applied are consistent and similar in the overall results of precision, accuracy, recall, and area under the ROC curve. Conclusions: 12 decision rules were defined based on the methods applied. The rules defined show motorcyclists, cyclists, including pedestrians, as the most vulnerable road users. Men and women motorcyclists between 20–39 years are prone in accidents with high severity. When a motorcycle or cyclist is not involved in the accident, the probable severity is low. © 2019, Springer Nature Switzerland AG.