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communication au 6th International Livestock farming systems symposium "Product quality based on local resources leading to improved sustainability" (2003); In Reunion Island, the dynamism of the livestock farming sector together with a policy of support for the “Outermost Regions” and the development of the “Hauts” (heights) led to the appearance and expansion of the dairy and suckler cattle industries structured over a time span of 20 to 30 years. With 500 breeders, the two cooperatives are developing the production of milk and meat, which is respectively of 21.8 million litres and 1500 tonnes. They declare that their targets are to approximately double the production by the end of the decade. Combined with those of the sugar cane industry, these targets appear difficult to reach, in the present situation of land speculation and town and country planning. We put forward the hypothesis that the farming industries must seek new forms of territorial coordination, for the continuation of their development. Complementarities must be found between the sectors, as forage and effluents transfers between lowlands and highlands. This evolution has to take part of the future changes on environmental standards (setting up of a National Park). We present some examples of the research work undertaken by the Cirad cattle-farming centre in partnership with the production and processing networks, for the purpose of providing references and decision support tools.

In queueing theory one seeks to predict in quantitative terms the congestion delays that occur when jobs or customers complete for processing resources. At present no satisfactory methods exist for the analysis of systems that allow simultaneous performance of tasks associated with a single job or customer. We present a heavy traffic analysis for the class of homogeneous fork-join networks in which jobs are routed in a feedforward deterministic fashion. We show that under certain regularity conditions the vector of total job count processes converges weakly to a multidimensional reflected Brownian motion (RBM) whose state space is a polyhedral cone in the nonnegative orthant. Furthermore, the weak limits of workload levels and throughput times are shown to be simple transformations of the RBM. As will be explained, the "steady-state throughput time" (a random variable) is expressed in terms of workload levels via the "longest path functional" of classical PERT/CPM analysis.

The Set Covering Problem (SCP) and the Set Partitioning Problem (SPP) represent an important class of all-binary (0-1) Integer Linear Programs (ILP). A review of the literature reveals extensive application of the SPP/SCP model to a wide set of practical problems. The basic model is explained, and then many of the actual applications of this powerful model discovered in the literature review are discussed. The problems derived from these applications are difficult to solve with any method, and are particularly difficult to solve with optimal or exact algorithms. Various solution techniques are investigated within the framework of the classical simplex method with branch and bound enumeration. Several reformulations of the SPP/SCP as Integer Generalized Networks are examined Extensive computational results are reported for several "real world" large-scale problems, and a convenient, compact format for data input is proposed as a standard for this problem class. http://archive.org/details/computationaldva1094520103 Captain, United States Marine Corps Approved for public release; distribution is unlimited.