Construction of the NASA thesaurus - Computer processing support Final report

Computer processing support for NASA Thesauru

Minnesota Agricultural Economist 697

Livestock Production/Industries,

MARKETING COSTS AND EFFICIENCY FOR AGRICULTURAL PRODUCTS: SOME CONCEPTUAL ISSUES IN ANALYSIS AND MEASUREMENT

Marketing,

Strings in gravity with torsion

A theory of gravitation in 4D is presented with strings used in the material action in $U_4$ spacetime. It is shown that the string naturally gives rise to torsion. It is also shown that the equation of motion a string follows from the Bianchi identity, gives the identical result as the Noether conservation laws, and follows a geodesic only in the lowest order approximation. In addition, the conservation laws show that strings naturally have spin, which arises not from their motion but from their one dimensional structure.Comment: 16 page

FEED PROCUREMENT METHODS FOR SOUTHEASTERN MINNESOTA DAIRY FARMS: A COMPARISON USING LP ANALYSIS

The principal objective of this study is to determine the financial impacts of changing feed procurement strategies for a specified southeastern Minnesota dairy farm. Growing all feed for the dairy herd on the farm itself, currently the most prominent mode of procurement, is compared to: (1) producing all forage and purchasing all concentrate feeds from others, and (2) purchasing all feeds from others. The effect of herd size on the comparisons is considered to determine if size has a bearing on the chosen method of feed procurement.Livestock Production/Industries,

COMPARATIVE COSTS OF DAIRY MARKETING IN NORWAY AND THE U.S.

Technical marketing efficiency is an important component of comparative advantage that countries may possess in food marketing. This aspect of marketing efficiency may be affected by size of market(s), technology used, input costs, and institutional factors. With regard to the latter, Norwegian policy makers have asked whether the extensive regulation and monopolization by a single processing cooperative in the Norwegian dairy sector have resulted in technical inefficiency that leads to excessive costs of milk marketing. Excessive marketing costs could have three important impacts; increased prices for domestic consumers, reduced prices for farmers, and reduced competitiveness in international markets. International competitiveness is critical for Norway as it considers or is considered for admission to the European Community and as trade liberalization proceeds under the GATT. The purpose of this analysis was to develop and apply a method for comparing marketing costs between countries to provide some insight into relative marketing efficiency between countries.Livestock Production/Industries,

Mapping unstructured grid problems to the connection machine

We present a highly parallel graph mapping technique that enables one to solve unstructured grid problems on massively parallel computers. Many implicit and explicit methods for solving discretizated partial differential equations require each point in the discretization to exchange data with its neighboring points every time step or iteration. The time spent communicating can limit the high performance promised by massively parallel computing. To eliminate this bottleneck, we map the graph of the irregular problem to the graph representing the interconnection topology of the computer such that the sum of the distances that the messages travel is minimized. We show that, in comparison to a naive assignment of processors, our heuristic mapping algorithm significantly reduces the communication time on the Connection Machine, CM-2

Efficient ICCG on a shared memory multiprocessor

Different approaches are discussed for exploiting parallelism in the ICCG (Incomplete Cholesky Conjugate Gradient) method for solving large sparse symmetric positive definite systems of equations on a shared memory parallel computer. Techniques for efficiently solving triangular systems and computing sparse matrix-vector products are explored. Three methods for scheduling the tasks in solving triangular systems are implemented on the Sequent Balance 21000. Sample problems that are representative of a large class of problems solved using iterative methods are used. We show that a static analysis to determine data dependences in the triangular solve can greatly improve its parallel efficiency. We also show that ignoring symmetry and storing the whole matrix can reduce solution time substantially

Hybrid computer techniques for solving partial differential equations

Techniques overcome equipment limitations that restrict other computer techniques in solving trivial cases. The use of curve fitting by quadratic interpolation greatly reduces required digital storage space