216 research outputs found
MARKET FORCES AND CHANGES IN THE PLANT INPUT SUPPLY INDUSTRY
Agribusiness, Input Supply Industry, Fertilizer, Plant Nutrients, Seed, Capital, Market Forces, Structural Change, Porter’s Five Forces, Agribusiness, Q13, L10, L22, M22, L80,
How do Ontology Mappings Change in the Life Sciences?
Mappings between related ontologies are increasingly used to support data
integration and analysis tasks. Changes in the ontologies also require the
adaptation of ontology mappings. So far the evolution of ontology mappings has
received little attention albeit ontologies change continuously especially in
the life sciences. We therefore analyze how mappings between popular life
science ontologies evolve for different match algorithms. We also evaluate
which semantic ontology changes primarily affect the mappings. We further
investigate alternatives to predict or estimate the degree of future mapping
changes based on previous ontology and mapping transitions.Comment: Keywords: mapping evolution, ontology matching, ontology evolutio
An economic analysis of the corn production efficiency of Iowa farm firms
Disequilibria in product and factor markets force firms to adjust production and reallocate resources. In a dynamic economic environment, production efficiency will depend upon the technical and allocative abilities of farm operators. The human capital approach hypothesizes that technical and allocative abilities are learned as opposed to innate skills;Agriculture is a logical industry to choose for investigating sources of differential firm efficiency. Modern agriculture is characterized by dynamic product and factor markets, rapid technological advances and a relatively uncomplicated management structure. Conceptual models of agricultural production efficiency are formulated. A model of technical efficiency is constructed for analyzing differential rates of adoption and utilization of a single production technology. A model of allocative efficiency is developed for analyzing relative cost efficiency;The corn production efficiency of Iowa farm firms is investigated in the empirical specification and estimation of the models. The data set is the 1976 Iowa Family Farm Survey. The cross-sectional survey of 933 Iowa farm families was designed and conducted by the Statistical Laboratory of Iowa State University;Technical efficiency is analyzed for the type of tillage practice used in corn production. A regression model including variables for profitability and human capital is specified for analyzing differential rates of adoption and utilization of reduced tillage practices. Empirical results indicate that operators of farms with larger corn enterprises, relatively large soybean enterprises, and light, sandy soils will more likely adopt and more fully utilize reduced tillage practices. In addition, the estimates indicate that operators who have completed more years of formal schooling and who frequently utilize information from agricultural extension programs more likely adopt and more fully utilize reduced tillage practices;Allocative efficiency is analyzed for relative cost efficiency in corn production. A measure of relative cost efficiency, the percentage by which actual variables cost differs from a theoretical minimum cost, is derived. A regression model including variables for scale and human capital is specified for analyzing differential cost efficiency. Although there exists considerable noise in the model, empirical results indicate that operators with greater years of farm management experience are more cost efficient relative to operators with fewer years of experience
A Grid Middleware for Ontology Access
Many advanced grid applications need access to ontologies represent-ing knowledge about a certain application domain. To deal with the high heterogeneity of available ontologies, we propose a general ser-vice-oriented middleware for making ontologies accessible to grid ap-plications. Our implementation is integrated in the German D-Grid in-frastructure and provides several applications a uniform access to biomedical ontologies such as Gene Ontology, NCI Thesaurus and several OBO ontologies
Development of subsidiary sow-farrowing firms in Iowa
The pork industry has been modified by a series of innovations in production technologies and now may be modified by changes in the organizational form of ownership. Changes in technology have resulted in a movement of pork production from an uncontrolled to a controlled environment. Confinement structures are rapidly being adopted to house much of Iowa’s livestock, especially hogs.https://lib.dr.iastate.edu/specialreports/1079/thumbnail.jp
GOMMA: a component-based infrastructure for managing and analyzing life science ontologies and their evolution
<p>Abstract</p> <p>Background</p> <p>Ontologies are increasingly used to structure and semantically describe entities of domains, such as genes and proteins in life sciences. Their increasing size and the high frequency of updates resulting in a large set of ontology versions necessitates efficient management and analysis of this data.</p> <p>Results</p> <p>We present GOMMA, a generic infrastructure for managing and analyzing life science ontologies and their evolution. GOMMA utilizes a generic repository to uniformly and efficiently manage ontology versions and different kinds of mappings. Furthermore, it provides components for ontology matching, and determining evolutionary ontology changes. These components are used by analysis tools, such as the Ontology Evolution Explorer (OnEX) and the detection of unstable ontology regions. We introduce the component-based infrastructure and show analysis results for selected components and life science applications. GOMMA is available at <url>http://dbs.uni-leipzig.de/GOMMA</url>.</p> <p>Conclusions</p> <p>GOMMA provides a comprehensive and scalable infrastructure to manage large life science ontologies and analyze their evolution. Key functions include a generic storage of ontology versions and mappings, support for ontology matching and determining ontology changes. The supported features for analyzing ontology changes are helpful to assess their impact on ontology-dependent applications such as for term enrichment. GOMMA complements OnEX by providing functionalities to manage various versions of mappings between two ontologies and allows combining different match approaches.</p
Continuous optical generation of microwave signals for fountain clocks
For the optical generation of ultrastable microwave signals for fountain
clocks we developed a setup, which is based on a cavity stabilized laser and a
commercial frequency comb. The robust system, in operation since 2020, is
locked to a 100 MHz output frequency of a hydrogen maser and provides an
ultrastable 9.6 GHz signal for the interrogation of atoms in two caesium
fountain clocks, acting as primary frequency standards. Measurements reveal
that the system provides a phase noise level which enables quantum projection
noise limited fountain frequency instabilities at the low level. At the same time it offers largely maintenance-free
operation.Comment: 8 pages, 4 figure
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