Browsing by Author "Ferreira, Manuel A."
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- A queue model for recycling and dismantling motor vehiclesPublication . Ferreira, Manuel A.; Filipe, José A.; Coelho, ManuelWe study a situation in which, owing to the exhaustion of non-renewable energy sources, conventional motor vehicles will turn out of use. We consider two scenarios: recycling or dismantling these motor vehicles. M|G|∞ queue system is used to study the process. Through it, we conclude that if the rate of dismantling and recycling of motor vehicles is greater than the rate at which they become idle, the system will tend to get balanced. The model allows also performing a brief study about the recycling or dismantling economic interest.
- A queue model for recycling and. dismantling motor vehiclesPublication . Ferreira, Manuel A.; Filipe, José António; Coelho, ManuelWe study a situation in which, owing to the exhaustion of non-renewable energy sources, conventional motor vehicles will turn out of use. We consider two scenarios: recycling or dismantling these motor vehicles. M|G|°° queue system is used to study the process. Through it, we conclude that if the rate of dismantling and recycling of motor vehicles is greater than the rate at which they become idle, the system will tend to get balanced. The model allows also performing a brief study about the recycling or dismantling economic interest.
- The relevance of chaos theory to explain problems of overexploitation in fisheriesPublication . Filipe, José António; Ferreira, Manuel A.; Coelho, ManuelThe Mankind’s oldest concern inhabits necessarily on its survival. For thousands of years the Humanity always lived with an almost steady level in the way of living. Production followed the growth of the population. To the generality of the times and to the generality of the people, the historical rule was a life with the strictly necessary for the populations’ day-to-day. The development is an exception in the history of the Humanity that exists just for a period not longer than 250 years. The Humanity had never had a so significant, consistent and intense transformation in its History. In this period, a complete revolution in the life style of the world-wide population happened to the countries currently appointed as developed countries. However, its effects were not bordered to these zones. Its presence has been extensive to the whole world. In particular, with what it is assigned as external aid, the rich countries changed the stages of development of a great part of the globe, shortening the development stages of many countries and provoking several kinds of unbalances and disturbs (see, for example, what happened with vaccines on the field of health, with the pollution, with all the problems emerged on the feeding area and with other many forms of intrusion, with visible effects and heavy direct impacts). This development represents a large step for the Humanity. The comfort, the best levels of health and the best standards of life correspond to a set of advantages which medal reverse represents so big costs that their effects we are not able to study yet. It is not the progress and the development that may be contested but the way the societies do not find ways to get a supported and balanced development, respecting the principles of equity that must exist among our specie and the others. Throughout the 20th century the extreme exploitation of resources brought out very big concerns about their preservation
- The sustainable competitive positional advantage of English Dailies : A study for the State of Tamilnadu (India)Publication . Selvarasu, A.; Filipe, José; Ferreira, Manuel A.; Coelho, Manuel