54,697 research outputs found
Weed control strategies in organically grown carrots
This paper outlines a study to integrate elements of cultural, thermal and mechanical control methods in the production of late maincrop drilled organic carrots. Agronomic and economic findings are discusse
Horticultural weed control in organic systems – a modelling approach
This report was presented at the UK Organic Research 2002 Conference. Weed control is an important yet mainly unaddressed research issue in organic systems. At present there is little agronomic support to underpin weed management decisions. Computer modelling and simulation techniques may provide a valuable tool for understanding the nature and processes of the organic system thus generating knowledge and information of direct benefit to growers, which will aid in short and long term weed management strategies
Control and structural optimization for maneuvering large spacecraft
Presented here are the results of an advanced control design as well as a discussion of the requirements for automating both the structures and control design efforts for maneuvering a large spacecraft. The advanced control application addresses a general three dimensional slewing problem, and is applied to a large geostationary platform. The platform consists of two flexible antennas attached to the ends of a flexible truss. The control strategy involves an open-loop rigid body control profile which is derived from a nonlinear optimal control problem and provides the main control effort. A perturbation feedback control reduces the response due to the flexibility of the structure. Results are shown which demonstrate the usefulness of the approach. Software issues are considered for developing an integrated structures and control design environment
PRODUCT DIFFERENTIATION PROTECTION: DEVELOPING A STRATEGY FOR MULTIPLE PRODUCERS OF REGIONAL SPECIALTY CROPS
Specialty crops grown by multiple producers are often viewed by consumers as differentiated products that command a price premium. Since price premiums are dependent upon differentiation of an item from generic counterparts, specialty crops must have distinctive identities that cannot be copied or mimicked by others. Trademarks are normally employed to differentiate and protect products, but the limitation of trademarks to products from a single source means that differentiation of specialty crops grown by multiple producers may involve difficulties in precluding free riders from adopting the same name. Through a case study of Georgia's Vidalia Onions and an examination of producer price data, this article explores the problem of the protection of product differentiation of regional specialty crops grown by multiple producers.Agribusiness,
Manual for extending the laser specklegram technique to strain analysis of rotating components
The theory, techniques, and equipment necessary for extending laser speckle techniques to analyze stresses in rotating blades are described. Details for setting up the equipment, for timing the events, for data recording, and for data analysis are discussed. Finite element techniques are investigated for analysis of speckle data. Advantages and limitations of the finite element analysis for the speckle data are discussed. The finite element program is listed
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