865 research outputs found

    The human role in a progressive trend of foundry automation

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    An increasing competition in the foundry market focuses on more efficient methods of production. High quality and efficiency requirements, but also rising labor costs, will make the foundry production largely automated. Currently,molding on automatic lines accounts for 40 % of the foundry production in Poland. The article discusses organizational,technical and ergonomic implications of automation in production processes and presents the results of research carried out in this field in Polish foundries

    Memory texts and memory work: Performances of memory in and with visual media

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    The online version of this article can be found at: http://mss.sagepub.com/content/early/2010/05/24/175069801037003

    Ergonomic and work safety evaluation criteria of process excellence in the foundry industry

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    The article presents a concept of criteria assessment called the “process excellence” for ergonomics and work safety in enterprises of the foundry industry as well as points to the possibility of its application

    Ergonomic and work safety evaluation criteria of process excellence in the foundry industry

    Get PDF
    The article presents a concept of criteria assessment called the “process excellence” for ergonomics and work safety in enterprises of the foundry industry as well as points to the possibility of its application

    The Dimensionality of Genomic Information and Its Effect on Genomic Prediction

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    The genomic relationship matrix (GRM) can be inverted by the algorithm for proven and young (APY) based on recursion on a random subset of animals. While a regular inverse has a cubic cost, the cost of the APY inverse can be close to linear. Theory for the APY assumes that the optimal size of the subset (maximizing accuracy of genomic predictions) is due to a limited dimensionality of the GRM, which is a function of the effective population size (N(e)). The objective of this study was to evaluate these assumptions by simulation. Six populations were simulated with approximate effective population size (N(e)) from 20 to 200. Each population consisted of 10 nonoverlapping generations, with 25,000 animals per generation and phenotypes available for generations 1–9. The last 3 generations were fully genotyped assuming genome length L = 30. The GRM was constructed for each population and analyzed for distribution of eigenvalues. Genomic estimated breeding values (GEBV) were computed by single-step GBLUP, using either a direct or an APY inverse of GRM. The sizes of the subset in APY were set to the number of the largest eigenvalues explaining x% of variation (EIGx, x = 90, 95, 98, 99) in GRM. Accuracies of GEBV for the last generation with the APY inverse peaked at EIG98 and were slightly lower with EIG95, EIG99, or the direct inverse. Most information in the GRM is contained in ∌N(e)L largest eigenvalues, with no information beyond 4N(e)L. Genomic predictions with the APY inverse of the GRM are more accurate than by the regular inverse

    Genomic BLUP including additive and dominant variation in purebreds and F1 crossbreds, with an application in pigs

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    Background: Most developments in quantitative genetics theory focus on the study of intra-breed/line concepts. With the availability of massive genomic information, it becomes necessary to revisit the theory for crossbred populations. We propose methods to construct genomic covariances with additive and non-additive (dominance) inheritance in the case of pure lines and crossbred populations. Results: We describe substitution effects and dominant deviations across two pure parental populations and the crossbred population. Gene effects are assumed to be independent of the origin of alleles and allelic frequencies can differ between parental populations. Based on these assumptions, the theoretical variance components (additive and dominant) are obtained as a function of marker effects and allelic frequencies. The additive genetic variance in the crossbred population includes the biological additive and dominant effects of a gene and a covariance term. Dominance variance in the crossbred population is proportional to the product of the heterozygosity coefficients of both parental populations. A genomic BLUP (best linear unbiased prediction) equivalent model is presented. We illustrate this approach by using pig data (two pure lines and their cross, including 8265 phenotyped and genotyped sows). For the total number of piglets born, the dominance variance in the crossbred population represented about 13 % of the total genetic variance. Dominance variation is only marginally important for litter size in the crossbred population. Conclusions: We present a coherent marker-based model that includes purebred and crossbred data and additive and dominant actions. Using this model, it is possible to estimate breeding values, dominant deviations and variance components in a dataset that comprises data on purebred and crossbred individuals. These methods can be exploited to plan assortative mating in pig, maize or other species, in order to generate superior crossbred individuals in terms of performance
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