No description available.

No description available.

No description available.

The purpose of this study was to develop and demonstrate an analytical framework to filter technical and economic information regarding alternative agricultural enterprises in order to enable farmers to make more informed diversification and adjustment decisions. This is particularly important for areas that need to adjust the structure of income sources as a result of dramatic changes in market demand and/or agricultural policy. Tobacco producing regions are currently facing such a problem in the United States. These regions need to consider a wide range of alternatives to maintain or enhance income and standards of living. The problem involved both strategic economic decisions and operational economic decisions. The method used combined information in the ArcView Geographic Information Systems (GIS) with Linear Programming (LP). Part of Pittsylvania County, Virginia, served as a case study example. A GIS database including soils and climatic conditions of the study area was created. Soils belonging to land capability classes 1 to 4 were considered for agricultural purposes. Agronomic requirements for specific yield levels of the enterprises considered were tabulated. An ArcView GIS analysis was conducted based on soil map unit symbols. Soil depth, soil series, soil texture, slope, flood potential and average summer temperature were factors associated with yield. Natural drainage, pH, natural fertility, content of organic matter and annual rainfall were factors that served for enterprise budget adjustments. The output of ArcView GIS analysis is maps of physically viable enterprise boundaries or enterprise reference units and tables of attributes for each field. Marketing of agricultural products that have prices that fluctuate seasonally is feasible only within the period of time called the "market window". When average historical prices were above total costs, a market window was identified. The optimal enterprise mix was addressed by LP from a whole farm planning perspective based on the results of ArcView GIS analysis and other constraints, including crop rotations, and irrigation limits. Various levels of tobacco production, vegetable enterprise activity levels, and limits on irrigation were employed to generate, ten scenarios. Results include the optimal enterprise mix, net revenue (above variable costs), shadow prices and sensitivity analysis. It is shown that specialty crops are not likely to replace tobacco income, at least in the near term. Developing a diversified farm plan could help farmers to make a smooth transition to other alternatives. / Ph. D.

This dissertation deals with a primal-dual conjugate subgradient-based algorithm for solving large-scale and/or specially structured linear programming problems. The proposed algorithm coordinates a Lagrangian dual function and a primal penalty function which satisfies a flexible set of specified properties, in order to generate a sequence of primal and dual iterates which can be shown to converge to an optimal pair of primal and dual solutions. Besides producing both primal and dual solutions, this coordination of primal and dual functions serves to guide the crucial choice of step-sizes in the iterative algorithm, and also provides a natural stopping criterion based on the duality gap. The generic algorithm maintains a considerable degree of flexibility which permits one to exploit any special structures inherent in the problem. Moreover, the algorithm admits a rich variety of admissible penalty functions and dual formulations in designing a particular implementation scheme. Other algorithmic strategies that can be gainfully employed to improve the performance of the algorithm include space-dilation and box step techniques, pattern search strategies and suboptimization based on complementary slackness conditions. The algorithm is tested on three different transportation problems with additional constraints which are faced by the Freight Equipment Management Program of the Association of American Railroads. Problem 1 is a maximin problem in which ∫(x) = minimum {∫,(x), r=1, ... , R} is maximized subject to the transportation constraints and a total cost constraint, where ∫, (·) is a savings function for the r^th railroad, for r=1, ... , R. Problem 2 minimizes weighted absolute deviations of ∫, (x); r=1, ... , R from its mean value subject to the Problem 1 constraint set. Problem 3, on the other hand, minimizes total cost subject to the transportation constraints and the constraint which requires each ∫, (x), r=1, ... , R to be at least at some desired level. Both theoretical issues concerning convergence properties and rates, as well as algorithmic design and computational performance issues are investigated. The results indicate that the algorithm is a viable strategy for these problems. In particular, a new conjugate gradient strategy emerges as a byproduct of this algorithm, which is shown to dominate other available strategies on standard test problems from the literature. / Ph. D.

Approved for public release, distribution is unlimited / .08B in shipping and redistribution costs of Not Ready for Issue (NRFI) materiel. This thesis models the NAVICP shipping of unserviceable but repairable (retrograde) Navy materiel or Depot Level Repairables (DLRs). It develops an integer linear program to prescribe minimum cost shipment recommendations of DLRs from fleet to repair locations within the NAVICP and Defense Logistics Agency (DLA) distribution system subject to constraints on average shipping time (AveTime). NAVICP provided data on DLR shipments for one year from which we construct six representative DLRs, 3 of aviation and 3 of maritime cognizance. We find a cost and time savings can be achieved for all representative DLRs by avoiding the use of DLA as storage prior to induction for repair. In this study we compare shipping costs for each of the six DLRs when we constrain AveTime, from 2 to 8 days. We find 2-day constrained AveTime shipping, on average, costs 18 times that of 7-day AveTime shipping, twice that of 3-day shipping and a minimum of 5 times and a maximum of 11 times that of the costs of 4 through 6-day shipping. / Lieutenant Commander, United States Navy

Chiu Chung-Bun. / Thesis (M.B.A.)--Chinese University of Hong Kong, 1986. / Includes bibliographical references (leaf 85).

Agricultural economics report 81. / Cover title. / "This manual supplements 'An iterative linear programming procedure for estimating patterns of agricultural land use,' by the present authors." / 28 p. tables

This paper presents a mathematical sizing algorithms of a stand alone and grid-connected photovoltaic-battery system for a residential house. The objective is to minimize the total storage capacity with cost of electricity. The proposed methodology is based on a Linear and Non-linear programming involving a real data collected through one year with reference to Hradec Kralove meteorological data and typical load profile in Czech Republic. The algorithm jointly optimizes the sizes of the photovoltaic and the battery systems by adjusting the battery charge and discharge cycles according to the availability of solar resource and a time-of-use tariff structure for electricity. The results show that jointly optimizing the sizing of battery and photovoltaic systems can significantly reduce electricity imports and the cost of electricity for the household. However, the optimal capacity of such photovoltaic battery varies strongly with the electricity consumption profile of the household, and is also affected by electricity and battery prices.

This paper presents a mathematical sizing algorithms of a grid-connected photovoltaic-battery system for a residential house. The objective is to minimize the total storage capacity with cost of electricity. The proposed methodology is based on a Linear and Non-linear programming. We have presents results from a existing PV panel FS-4115-3 for the given climatic conditions and the electricity use profile. Measurements for whole household electricity consumption have been obtained over a period of two months. They were all obtained at one hour interval. The algorithm jointly optimizes the sizes of the photovoltaic and the battery systems by adjusting the battery charge and discharge cycles according to the availability of solar resource and a time-of-use tariff structure for electricity. The results show that jointly optimizing the sizing of battery and photovoltaic systems can significantly reduce electricity imports and the cost of electricity for the household.