Recent highlights in the synthesis of highly functionalized pyrimidines

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Computational assessment of k-means clustering on a Structural Equation Model based index

This paper proposes an alternative method for the choice of the number of centroids in a cluster analysis, when the groups’ order is relevant. Differently from commonly used approaches, aimed at finding the minimum number of clusters, the illustrated method aims at finding the maximum one. Given that the clusters are ordered, this allows to define a granular ranking among them. The k-means partitioning algorithm is applied to an index resulting from a Structural Equation Model. The procedure is implemented on a measure of air pollution in urban areas: a clustering of main Italian cities, according to the optimal number of air pollution levels, is the final result. The analysis’ interpretation provides useful information to design policies aimed at reducing air pollution

Assessing environmental quality by clustering a structural equation model based index

This paper proposes an innovative computational procedure to determine the optimal number of clusters. The aim is to identify the maximum number of significantly distinct clusters, when the centroids are orderable and order is relevant. The insight is that ranking according to this optimal number of clusters allows to better classify units in order to assess their quality with regard to a variable of interest. By means of bootstrap confidence intervals estimated on clusters’ centroids, the procedure allows to identify the optimal number of “well-separated” groups. The centroids are obtained applying a unidimensional k-means clustering and they allow to classify and rank the measure of an Index based on a Structural Equation Model. The procedure ranks European cities according to their level of air pollution

An approach for computing AS/R systems travel times in a class-based storage configuration

This study provides an approach to compute the travel time for AS/R systems in a class-based storage environment. A regression analysis is completed in order to define the importance of the key predictors taken into account and to propose a formulation of travel times. The results show the reliability of the model and allow to evaluate the travel time through the identification of a complete list of predictors. The proposed approach supports managers in theex-ante definition of travel times for a warehouse. A correct evaluation of travel times enables a better monitoring of the performance of warehouse operations and can support practitioners in the choice of the configuration not only in terms of kind of cycle, but also from a policy assignment perspective. From a theoretical point of view, this work can be considered as an attempt to refine the existing methods to compute travel times

Implementation of Lean Manufacturing tools in emerging countries: evidence from Uzbek SMEs

It is known that Lean Manufacturing (LM) practices play a significant role in achieving lower costs, higher flexibility, and efficiency in production processes, in order to fit the requirement of today’s dynamic customer demand. A lot of literature contributions deal with the application of Lean in developed countries. However, few studies have been focused on integrating various Lean tools to optimize manufacturing processes in developing countries. In particular, a limited number of case studies address manufacturing in Small and Medium Enterprises (SMEs) in Central Asian countries. Thus, the purpose of this work is to investigate through a case study how LM can enhance the operational efficiency of an Uzbek aluminium profiles manufacturer. The proposed combination of different LM techniques, such as Value Stream Mapping (VSM), 5 W +1 H, and 5S, improved the overall performance of the production process at issue. Wasted time was reduced to 2% and 8% in press and painting shops respectively. Additionally, the total daily production rate was increased up to 30.1 t/day. LM application to emerging countries’ SMEs improves production effectiveness and helps to achieve higher levels of production standards, which leads to an increase export capability and market share in the international context

The Multi Crane Scheduling Problem: A Comparison Between Genetic Algorithm and Neural Network Approaches based on Simulation Modeling

The internal logistics for warehouses of many industrial applications, based on the movement of heavy goods, is commonly solved by the installment of a multi-crane system. The job scheduling of a multi-crane system is an interesting problem of optimization, solved in many ways in the past. This paper describes a comparison between the optimization by the use of Genetic Algorithms (GA) and introduce a framework for the solution of the problem using machine learning driven by Neural Networks (NN). Even though this last approach is not implemented in this paper, performances very close to GA ones are expected with NN. A case-study for steel coil production is proposed as a test frame for two different simulation software tools, one based on a heuristic solution and one on machine learning; performances and data achieved from reviews and simulations are compared

Optimization Model of a Tandem Water Reservoir System Management

This paper presents a complex approach for modelling of a tandem reservoir systems for water drainage management. The model has been built over a segment of a river with a certain parameters of water inflow, water outflow, required power production and max possible flood occurrence. Then the segments may be replicated with specific parameters to simulate whole system of the river. The model has been optimized in order to obtain the water drainage operation policy with regards of current and expected water volumes in the reservoirs ratio, required power production revenue, and minimal flood occurrence. Model has been verified on a walkthrough basis. The obtained results demonstrate good reliability disregards broad possible variations of the managed parameters and provide the optimal water drainage for minimum flood occurrence and desired power production revenue

Atributos de la experiencia de servicio en relación con la satisfacción del cliente e intención de comportamiento en restaurantes temáticos Retro’s de Lima Metropolitana

El presente trabajo de investigación, tiene como finalidad medir los atributos de la experiencia de servicio en relación con la satisfacción del cliente e intención de comportamiento en restaurantes temáticos Retro’s de Lima Metropolitana. Ello, permite entender cómo el consumidor al ir a un establecimiento de restaurante temático, percibe los atributos de la experiencia, llevándolo a generar satisfacción y, posteriormente a una intención de comportamiento favorable o desfavorable. En relación a la metodología fue de carácter cuantitativa no correlacional, la cual se realizó mediante encuestas usando el muestreo no probabilístico. Para la elaboración del cuestionario, se procedió a sub dividirlo en siete partes (Preguntas demográficas, calidad de servicio, calidad de la comida, atmósfera, autenticidad, satisfacción del cliente e intención de comportamiento. Además, el cuestionario fue trabajado con la escala de likert del 1 al 7 y del 1 al 5. Cabe resaltar, que el cuestionario posee una extensión de 46 preguntas, lo cual nos permite entender de manera más exacta las necesidades, preferencias y percepciones del consumidor.The purpose of this research work is to measure the attributes of the service experience in relation to customer satisfaction and intention to behave in Retro's themed restaurants in Metropolitan Lima. This allows us to understand how the consumer, when going to a thematic restaurant establishment, perceives the attributes of the experience, leading him to generate satisfaction and, later, to an intention of favorable or unfavorable behavior. Regarding the methodology, it was of a non-correlational quantitative nature, which was carried out through surveys using non-probabilistic sampling. For the elaboration of the questionnaire, it was divided into seven parts (demographic questions, quality of service, quality of food, atmosphere, authenticity, customer satisfaction and behavioral intention. In addition, the questionnaire was worked with the likert scale from 1 to 7 and from 1 to 5. It should be noted that the questionnaire has an extension of 46 questions, which allows us to understand more precisely the needs, preferences and perceptions of the consumer.Trabajo de investigació