170 research outputs found
Howard T. Odum et Elisabeth C. Odum, 2008, A Prosperous Way Down: Principles and Policies, University Press of Colorado, (2001 pour la 1ère edition), 348 p.
No full textHoward T. Odum (1924-2002) fait partie de ces auteurs qui, dès les années 1970 et avec une remarquable constance, se sont inquiétés de la périlleuse trajectoire prise par le développement de l’humanité, et de ses angoissantes conséquences environnementales. Il reste pourtant méconnu en France, où il est souvent l’un des oubliés dans les listes des « précurseurs » de l’écologie politique. L’essai A Prosperous Way Down, co-écrit avec sa femme Elisabeth C. Odum et initialement publié en 2001, no..
A tight bound on the throughput of queueing networks with blocking
No full textIn this paper, we present a bounding methodology that allows to compute a tight lower bound on the cycle time of fork--join queueing networks with blocking and with general service time distributions. The methodology relies on two ideas. First, probability masses fitting (PMF) discretizes the service time distributions so that the evolution of the modified network can be modelled by a Markov chain. The PMF discretization is simple: the probability masses on regular intervals are computed and aggregated on a single value in the orresponding interval. Second, we take advantage of the concept of critical path, i.e. the sequence of jobs that covers a sample run. We show that the critical path can be computed with the discretized distributions and that the same sequence of jobs offers a lower bound on the original cycle time. The tightness of the bound is shown on computational experiments. Finally, we discuss the extension to split--and--merge networks and approximate estimations of the cycle time.queueing networks, blocking, throughput, bound, probability masses fitting, critical path.
Probability masses fitting in the analysis of manufacturing flow lines
No full textA new alternative in the analysis of manufacturing systems with finite buffers is presented. We propose and study a new approach in order to build tractable phase-type distributions, which are required by state-of-the-art analytical models. Called "probability masses fitting" (PMF), the approach is quite simple: the probability masses on regular intervals are computed and aggregated on a single value in the corresponding interval, leading to a discrete distribution. PMF shows some interesting properties: it is bounding, monotonic and it conserves the shape of the distribution. After PMF, from the discrete phase-type distributions, state-of-the-art analytical models can be applied. Here, we choose the exactly model the evolution of the system by a Markov chain, and we focus on flow lines. The properties of the global modelling method can be discovered by extending the PMF properties, mainly leading to bounds on the throughput. Finally, the method is shown, by numerical experiments, to compute accurate estimations of the throughput and of various performance measures, reaching accuracy levels of a few tenths of percent.stochastic modelling, flow lines, probability masses fitting, discretization, bounds, performance measures, distributions.
The evolutionary history of Neanderthal and Denisovan Y chromosomes
No full textQ.F. was supported by funding from the Chinese Academy of Sciences (XDB26000000) and the National Natural Science Foundation of China (91731303, 41925009, 41630102). A.R. was funded by Spanish government (MICINN/FEDER) (grant number CGL2016-75109-P). The reassessment of the Spy collection by H.R., I.C., and P.S. was supported by the Belgian Science Policy Office (BELSPO 2004-2007, MO/36/0112).
M.V.S., M.B.K., and A.P.D. were supported by the Russian
Foundation for Basic Research (RFBR 17-29-04206). This study
was funded by the Max Planck Society and the European
Research Council (grant agreement number 694707)Petr, M., Hajdinjak, M., Fu, Q., Essel, E., Rougier, H., Crevecoeur, I., Semal, P., Golovanova, L.V., Doronichev, V.B., Lalueza-Fox, C., De la Rasilla, M., Rosas, A., Shunkov, M.V., Kozlikin, M.B., Derevianko, A.P., Vernot, B., Meyer, M., Kelso, J
Design of a network of reusable logistic containers
No full textIn this paper, we consider the management of the return flows of empty logistic containers that accumulate at the customer’s sites. These containers must be brought back to the factories in order to sustain future expeditions. We consider a network composed of several factories and several customers in which the return flows are independent of the delivery flows. The models and their solutions aim at finding to which factory the contain- ers have to be brought back and at which frequency. These frequencies directly define the volume of logistic containers to hold in the network. We consider fixed transportation costs depending on the locations of the customers and of the factories and linear holding costs for the inventory of logistic containers. The analysis also provides insight on the benefit of pooling the containers among different customers and/or factories.supply chain management, returnable items, reverse logistic, economic order quantity, network design
The body, health, and healing in alternative and integrated medicine: An ethnography of homeopathy in South London
No full textThis thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University, 07/02/2003.During the recent exponential rise in the use of alternative medicines (AM) in the West and increasing integration into the health service, little research has been done on AM in the context in which it is practised, or over time to look at changing belief systems. This thesis provides an anthropologically informed analysis of one alternative therapy in depth - homeopathy- explored from the multiple perspectives of biomedical and lay homeopaths, users and students of homeopathy. The ethnography comprised 18 months participant observation in 4 settings in south London: the surgery of a homeopathic GP; a homeopathy adult education class; a vaccination support group; and a low cost homeopathy clinic for victims of crime. The fieldwork is contextualised by a critique of the existing research on users of AM; a review of the history and politics of integration of AM and a review of anthropological conceptions of the body and health. Analysis of the empirical data reveals different groups of users of homeopathy with differing beliefs around health, healing and the body. 'Pragmatic users' had a normative biomedical view of health. 'Committed users' moved away from the normative biomedical position and were enculturated into a different view of health and the body through interaction with lay homeopaths. Inherent in these practitioners' and users' beliefs and practices were a number of oppositions to science-based medicine. Prolonged fieldwork enabled the changing views of users to be charted as they moved from biomedical to alternative views. The medical homeopath stayed allied to many biomedical beliefs about the body and health, partly as a result of general practice constraints of time, colleagues and training. Tensions between his biomedical and homeopathic practice lead to paradoxical behaviours that confused his patients. These findings problematise the notion of integration, of trying to incorporate two opposing ideologies into one system. Implications for alternative medicine more widely are discussed.NHS Executive London Regio
GSK Vaccines NA RDC: Project rationale review and Key Performance Indicators selection
No full textGSK Vx is currently reviewing its distribution Network Strategy. The current distribution network is highly concentrated in Europe with direct shipments by air to the clients. The distribution center in Gembloux is responsible for 80% of the vaccines volume shipped to clients worldwide. This fragmented view and control of the distribution lead to a supply continuity and security risk. The new model will consist on the implementation of regional distribution centers to push the products closer to the markets. To implement the new model, a pilot project has been designed, the NA RDC. The project is to implement a distribution center in the US that will be responsible of supplying US, Canada and Mexico markets. For such a project to be endorsed, a presentation has been done to the higher management. The thesis will consist in the review of the business case that supported the management endorsement and the building of KPI associated to prove the project impact and benefits. The goal was to create a framework using literature from different fields. Vaccine distribution network and performance literature combined with decentralized vs decentralized literature has been used to create a list of attention points regarding vaccine decentralized distribution. The SCOR and SMART models have been used to ensure the quality and strategic relevance of the KPI that were built. The outcome was a list of KPI based on the review of the business case that the author conducted.Master [120] en Ingénieur de gestion, Université catholique de Louvain, 2018La diffusion de ce mémoire n'est pas autorisée par l'institutio
Building a Travel Influencer Brand Using Instagram Tool
No full textThe aim of this diploma paper is to present the model of what Instagram tools should a newly created travel influencer trademark use in order to create values to become a brand. The theoretical part of this paper contains literature analysis of differences between trademark and brand; branding; social media and Instagram; travel industry phenomenon written by different authors. The second part of this paper contains results of the research of travel influencer brands and the results of a travel influencer trademark created by the author Traveler’s Child. In addition, types of visual content are introduced in order to differentiate content posted by brands and trademark. The last part of this paper contains the recommendations for travel influencer trademark owners on how to process through branding stages, while using Instagram tools in order to achieve the creation of intangible values, which allows a trademark to become a brand.Master [120] en sciences de gestion, Université catholique de Louvain, 201
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