Scheduling of non-repetitive lean manufacturing systems under uncertainty using intelligent agent simulation

World-class manufacturing paradigms emerge from specific types of manufacturing systems with which they remain associated until they are obsolete. Since its introduction the lean paradigm is almost exclusively implemented in repetitive manufacturing systems employing flow-shop layout configurations. Due to its inherent complexity and combinatorial nature, scheduling is one application domain whereby the implementation of manufacturing philosophies and best practices is particularly challenging. The study of the limited reported attempts to extend leanness into the scheduling of non-repetitive manufacturing systems with functional shop-floor configurations confirms that these works have adopted a similar approach which aims to transform the system mainly through reconfiguration in order to increase the degree of manufacturing repetitiveness and thus facilitate the adoption of leanness. This research proposes the use of leading edge intelligent agent simulation to extend the lean principles and techniques to the scheduling of non-repetitive production environments with functional layouts and no prior reconfiguration of any form. The simulated system is a dynamic job-shop with stochastic order arrivals and processing times operating under a variety of dispatching rules. The modelled job-shop is subject to uncertainty expressed in the form of high priority orders unexpectedly arriving at the system, order cancellations and machine breakdowns. The effect of the various forms of the stochastic disruptions considered in this study on system performance prior and post the introduction of leanness is analysed in terms of a number of time, due date and work-in-progress related performance metrics

The Value of an Enterprise Postgraduate Research Programme for creating business start-ups in the UK

The Masters of Enterprise Programme is a postgraduate programme whereby a student attempts to start a business during the course of their studies. Established in 2001, we have analysed the success of the 59 companies created from the course and found that as expected the start-up rate is higher than the general population. We also found that ratio of male to female founders (70-30) was similar to start-ups from the general population; however, the survival rate of ventures created from the programme was significantly higher. Also, a higher rate of the businesses were employing more than just the founder, implying they are what could be considered “Entrepreneurial” businesses rather than simply someone self- employed as might be normal in some careers. Despite many overseas students completing the course, only 3 of the businesses were founded outside the UK, suggesting the UK economy is benefitting from the ventures created. We also discuss other outcomes from the course such as these entrepreneurial students are often recruited by top corporates. We further discuss what we believe are the contributing pedagogic factors to its success.   Keywords: Entrepreneurship and Enterprise Education, Employability, Start-ups, UK economy.Papadopoulou, KA.; Phillips, RA. (2020). The Value of an Enterprise Postgraduate Research Programme for creating business start-ups in the UK. En 6th International Conference on Higher Education Advances (HEAd'20). Editorial Universitat Politècnica de València. (30-05-2020):659-667. https://doi.org/10.4995/HEAd20.2020.11122OCS65966730-05-202

Searching edges in the overlap of two plane graphs

Consider a pair of plane straight-line graphs, whose edges are colored red and blue, respectively, and let n be the total complexity of both graphs. We present a O(n log n)-time O(n)-space technique to preprocess such pair of graphs, that enables efficient searches among the red-blue intersections along edges of one of the graphs. Our technique has a number of applications to geometric problems. This includes: (1) a solution to the batched red-blue search problem [Dehne et al. 2006] in O(n log n) queries to the oracle; (2) an algorithm to compute the maximum vertical distance between a pair of 3D polyhedral terrains one of which is convex in O(n log n) time, where n is the total complexity of both terrains; (3) an algorithm to construct the Hausdorff Voronoi diagram of a family of point clusters in the plane in O((n+m) log^3 n) time and O(n+m) space, where n is the total number of points in all clusters and m is the number of crossings between all clusters; (4) an algorithm to construct the farthest-color Voronoi diagram of the corners of n axis-aligned rectangles in O(n log^2 n) time; (5) an algorithm to solve the stabbing circle problem for n parallel line segments in the plane in optimal O(n log n) time. All these results are new or improve on the best known algorithms.Comment: 22 pages, 6 figure

Efectos de los métodos de procesado y de las condiciones de almacenamiento comercial en los índices de calidad del aceite virgen extra

The effect of machinery groups, packing materials and light intensities was ascertained on indices of oxidative deterioration, peroxide value, and extinction coefficient K232 and K270 of extra virgin olive oil for one season of olive harvesting in an effort to simulate commercial storage conditions. It was revealed that during the storage of olive oil the peroxide value was significantly affected by the type of extraction machinery, packing material and light intensity. It is significant that oil exposed to diffused daylight and artificial light attained maximum PV in the second or third month of storage and de creased thereafter, while samples stored in the dark attained their maximum PV during the sixth month of storage. Oil samples extracted using the centrifugal type of machines and kept in glass containers in the dark had higher peroxide values than those extracted by the classic method. The rate of changes of the PV and the two indices K232 and K270 was also affected similarly by the type of machinery, packing material and light intensity.El efecto de la maquinaria, el material de envasado y la intensidad de luz fue relacionado con los índices de deterioración oxidativa, índice de peróxidos (IP) y coeficientes de extinción K232 y K270 del aceite de oliva virgen extra durante una campaña de cosecha de aceituna en un esfuerzo por simular las condiciones de almacenamiento comercial. Esto reveló que durante el almacenamiento del aceite de oliva el índice de peróxidos fue afectado significativamente por el tipo de maquinaria de extracción, el material de envasado y la intensidad de luz. Es significativo que el aceite expuesto a la luz diaria difusa y a la artificial alcanzara el máximo IP en el segundo o tercer mes de almacenamiento, decreciendo a partir de este momento, mientras que las muestras almacenadas en oscuridad no alcanzaban su máximo IP hasta el sexto mes de conservación. Las muestras de aceite extraídas con centrífuga y mantenidas en contenedores vidrio en la oscuridad alcanzaron un IP mayor que las extraídas por el sistema clásico. Las velocidades de cambio del IP y de los K232 y K270 fueron también afectadas por el tipo de maquinaria extractora empleada, el material de envasado utilizado y la intensidad de luz recibida por el aceite durante su conservación

Counterfeit purchase typologies during an economic crisis

Purpose-The economic crisis has become a global phenomenon, although in Europe it mostly affected the Mediterranean countries of Southern Europe. In times of economic stress, counterfeit products increase their market share. In this context this paper aims to explore, and attempt to explain, consumer perspectives on the purchasing of counterfeit brands. Methodology-The study utilized an e-mail based open ended questionnaire as its data collection method. The research used a sample of 83 participants belonging to generation Y (younger and older) and upper medium and high income class brackets. Findings-Purchasing behaviour of counterfeit products during the economic crisis enabled us to identify four types of consumers. Furthermore, the results indicated that some consumers have significant interest in counterfeits while some consumers show apathy or indifference towards counterfeiting. Furthermore, some consumers believe that the government’s economic austerity policies cause high level consumption of counterfeits while others consider the authorities to be responsible for counterfeiting, since they do not adequately tackle it. Research limitations/implications- This research is exploratory in nature and restricted to Greek generation Y consumers. Suggestions are presented regarding future studies and generalization of the findings. Practical implications- Implementation of law, joint communication campaigns and social media usage are the major implications for the stakeholders in the marketplace. Originality/value-This study extends the body of knowledge of purchasing behavior on non-deceptive counterfeit products by offering empirical findings from Greece, a country facing a severe economic crisis. To our knowledge this is the first study that explores counterfeit buying behaviour during an economic crisis perio