28,127 research outputs found
What can research deliver for organic farming?
The research needs of any applied subject are always influenced by three major groups of criteria. These are the economic/political, the societal/ethical and the technical/scientific. This is especially the case for Organic Farming which explicitly sets out to present a positively value based approach to agriculture, an activity, which has commonly become dominated by the commercial economics of an industrial society. To maintain this ethical stance Organic Farming must challenge some of the tenets of conventional economics and politics and must work within the particular societal context. Its scientific needs are then driven either by the need to increase its role in terms of market share or the need to achieve its aims more effectively in respect of product quality and/or delivery of environmental goods. In this paper I examine the current opportunities for Organic Farming in relation to the present state of farming economics and the current expectations of society, considering both food production and the delivery of environmental services which are paid from the public purse, e.g. via the Common Agricultural Policy (CAP). I use these criteria to analyse what are the current primary research needs in relation to the science and ethical base of Organic Agriculture
Telerobot task planning and reasoning: Introduction to JPL artificial intelligence research
A view of the capabilities and areas of artificial intelligence research which are required for autonomous space telerobotics extending through the year 2000 is given. In the coming years, JPL will be conducting directed research to achieve these capabilities, as well as drawing heavily on collaborative efforts conducted with other research laboratories
A Computational Routine for Disaggregating Industry Margin Data to Estimate Product Margin Rates
Retail industry product margin rates are used to estimate the retail output proportion of final consumption commodities. The Census Bureau collects data on industry margin rates, but it does not collect product margin rate data. To estimate retail industry-by-commodity output, industry margin rates are disaggregated by product. A number of controls are available for disaggregating industry data. This paper introduces a formal computational method for disaggregating industry margin data using Bayesian statistics and simulation. The routine is capable of accurately imposing multiple controls simultaneously. The method's accuracy is demonstrated by an evaluation of its industry product margin rate estimates. In addition to producing accurate disaggregate estimates, the method is fast and its estimates are replicable. The computational method has a broad range of applications beyond the estimation of industry-by-product margin rates.
The Case for Improving U.S. Computer Science Education
Despite the growing use of computers and software in every facet of our economy, not until recently has computer science education begun to gain traction in American school systems. The current focus on improving science, technology, engineering, and mathematics (STEM) education in the U.S. school system has disregarded differences within STEM fields. Indeed, the most important STEM field for a modern economy is not only one that is not represented by its own initial in "STEM" but also the field with the fewest number of high school students taking its classes and by far has the most room for improvement—computer science
Pattern classes and priority queues
When a set of permutations comprising a pattern class C is submitted as input
to a priority queue the resulting output is again a pattern class C'. The basis
of C' is determined for pattern classes C whose basis elements have length 3,
and is finite in these cases. An example is given of a class C with basis 2431
for which C is not finitely based
Permutation Classes of Polynomial Growth
A pattern class is a set of permutations closed under the formation of
subpermutations. Such classes can be characterised as those permutations not
involving a particular set of forbidden permutations. A simple collection of
necessary and sufficient conditions on sets of forbidden permutations which
ensure that the associated pattern class is of polynomial growth is determined.
A catalogue of all such sets of forbidden permutations having three or fewer
elements is provided together with bounds on the degrees of the associated
enumerating polynomials.Comment: 17 pages, 4 figure
Atmospheric chemistry of gas-phase polycyclic aromatic hydrocarbons: formation of atmospheric mutagens.
The atmospheric chemistry of the 2- to 4-ring polycyclic aromatic hydrocarbons (PAH), which exist mainly in the gas phase in the atmosphere, is discussed. The dominant loss process for the gas-phase PAH is by reaction with the hydroxyl radical, resulting in calculated lifetimes in the atmosphere of generally less than one day. The hydroxyl (OH) radical-initiated reactions and nitrate (NO3) radical-initiated reactions often lead to the formation of mutagenic nitro-PAH and other nitropolycyclic aromatic compounds, including nitrodibenzopyranones. These atmospheric reactions have a significant effect on ambient mutagenic activity, indicating that health risk assessments of combustion emissions should include atmospheric transformation products
The EMC of satellite power systems and DoD C-E systems
The solar power satellite (SPS) technical parameters that are needed to accurately assess the electromagnetic compatibility (EMC) between SPS systems and DoD communications-electronics (C-E) systems are identified and assessed. The type of electromagnetic interactions that could degrade the performance of C-E systems are described and the major military installations in the southwestern portions of CONUS where specially sensitive C-E systems are being used for combat training and evaluation are identified. Classes of C-E systems that are generally in the vicinity of these military installations are considered. The Technical parameters that govern the degree of compatibility of the SPS with these C-E systems, and some technical requirements that are necessary to ensure short-term and long-term EMC are identified
Sorting with a forklift
A fork stack is a generalised stack which allows pushes and pops of several
items at a time. We consider the problem of determining which input streams can
be sorted using a single forkstack, or dually, which permutations of a fixed
input stream can be produced using a single forkstack. An algorithm is given to
solve the sorting problem and the minimal unsortable sequences are found. The
results are extended to fork stacks where there are bounds on how many items
can be pushed and popped at one time. In this context we also establish how to
enumerate the collection of sortable sequences.Comment: 24 pages, 2 figure
Adapting structuration theory to understand the role of reflexivity: Problematization, clinical audit and information systems
This paper is an exploratory account of the further development and application of a hybrid framework,
StructurANTion, that is based on Structuration Theory and Actor Network Theory (ANT). The use of social
theories in general and their use in information systems (IS) research in particular is explored leading to
the use of the framework to examine the concept of what are termed humanchine networks in the context
of clinical audit, within a healthcare Primary Care Trust (PCT). A particular focus is on the manner in which
information systems-based reflexivity contributes to both entrenching a networks’ structurated order as
well as contributing to its emancipatory change. The case study compares clinic-centric and patientcentric
audit and seeks to further extend the understanding of the role of information and information
systems within structurated humanchine activity systems. Conclusions indicate that the use of more
socially informed IS methods and approaches can incorporate more emancipatory ideals and lead to
greater adoption and usage of more relevant and useful clinical information systems and practices
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