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| Registros recuperados: 33 | |
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| PELOIA,PAULO R.; RODRIGUES,LUIZ H. A.. |
| ABSTRACT In order to achieve more efficient agricultural production systems, studies relating to the patterns of influence factors on commercial blocks of outstanding performance can be performed to assist management practices. The performance is considered to be the difference between the yield of a given block and the average yield of the homogeneous group that it belongs to. The methods available to identify these outstanding blocks are usually subjective. The aim of this study was to propose an objective and repeatable approach to identify outstanding performance blocks. The proposed approach consisted of performance determination, using regression trees, and the classification of these blocks by k-means clustering. This approach was illustrated using... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Clustering; Regression tree; Yield variability. |
| Ano: 2016 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-69162016000500895 |
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| Reis,Marcelo S.; Takita,Marco A.; Palmieri,Darío A.; Machado,Marcos A.. |
| In this work we describe all the computational environments, pipelines, and web services developed for the CitEST transcriptome project, on which all the annotation researchers relied. We also present a complete list of CitEST libraries and, for each of them, the general features after the in silico processing, showing some quantitative information. |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Transcriptomics; Comparative genomics; Clustering; Trimming; Digital northern. |
| Ano: 2007 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572007000500031 |
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| Lanctot, Jl; Legendre, P; Salvat, B. |
| The resistance to perturbations of reef-dwelling gastropod assemblages was studied on the seaward reefs of Fangataufa atoll (French Polynesia) after their exposure to atmospheric nuclear tests, a major man-made perturbation. We focused on two important aspects: (1) the temporal evolution of the densities of the most important species before and after the tests, and (2) the temporal evolution of the spatial structure of the assemblages. Three transects, crossing several geomorphological zones, were established on the seaward reefs of the atoll. Each transect was sampled at irregular time intervals during a twenty-year period. Several univariate and multivariate methods were used to study (1) the temporal fluctuations in species abundances and ranks, and (2)... |
| Tipo: Text |
Palavras-chave: Atmospheric nuclear tests; Clustering; Coral reefs; Gastropods; Perturbation. |
| Ano: 1997 |
URL: http://archimer.ifremer.fr/doc/00093/20394/18061.pdf |
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| Marques, Virginie; Guérin, Pierre-édouard; Rocle, Mathieu; Valentini, Alice; Manel, Stéphanie; Mouillot, David; Dejean, Tony. |
| Human activities impact all ecosystems on Earth, which urges scientists to better understand biodiversity changes across temporal and spatial scales. Environmental DNA (eDNA) metabarcoding is a promising non‐invasive method to assess species composition in a wide range of ecosystems. Yet, this method requires the completeness of a reference database, i.e. a list of DNA sequences attached to each species of the regional pool, which is rarely met. As an alternative, molecular operational taxonomic units (MOTUs) can be extracted as clusters of sequences. However, the extent to which the diversity of MOTUs can predict the diversity of species across spatial scales is unknown. Here, we used 196 samples along the Rhone river (France) for which the reference... |
| Tipo: Text |
Palavras-chave: 12S primer; Alpha-beta-delta-diversity; Clustering; Metabarcoding; MOTUs; Reference database. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00643/75506/76373.pdf |
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| Grassi, Kelly; Poisson-caillault, Emilie; Bigand, André; Lefebvre, Alain. |
| In the framework of ecological or environmental assessments and management, detection, characterization and forecasting of the dynamics of environmental states are of paramount importance. These states should reflect general patterns of change, recurrent or occasional events, long-lasting or short or extreme events which contribute to explain the structure and the function of the ecosystem. To identify such states, many scientific consortiums promote the implementation of Integrated Observing Systems which generate increasing amount of complex multivariate/multisource/multiscale datasets. Extracting the most relevant ecological information from such complex datasets requires the implementation of Machine Learning-based processing tools. In this context, we... |
| Tipo: Text |
Palavras-chave: Clustering; Pattern discovery; Time series; Multi-Level Spectral Clustering; English Channel. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00643/75481/76326.pdf |
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| Feucher, Charlene; Maze, Guillaume; Mercier, Herle. |
| In the north Atlantic subtropical gyre, the oceanic vertical structure of density is characterized by a region of rapid increase with depth. This layer is called the permanent pycnocline because this density feature is observed throughout the year. The pycnocline is the transition layer between light, low-latitude, surface water masses which are ventilated every winter when penetrated locally by the mixed layer and dense, deeper water masses whose properties are set in the high latitudes and circulate equatorward. In-situ data from the Argo array provide temperature/salinity profiles allowing the characterization in space and time of the permanent pycnocline. We thus developed a new method to characterize its depth, thickness and thermohaline... |
| Tipo: Text |
Palavras-chave: Argo; Quality Control; Pattern; Clustering; North Atlantic; Subtropical gyre; Stratification. |
| Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00242/35315/33838.pdf |
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| Gailhard-rocher, Isabelle; Huret, Martin; Lazure, Pascal; Vandermeirsch, Frederic; Gatti, Julie; Garreau, Pierre; Gohin, Francis. |
| Dans le contexte de l’évaluation initiale des eaux communautaires demandée par la Directive cadre stratégie pour le milieu marin (DCSMM), les états membres sont chargés de décrire les types d’habitats dominants de la colonne d’eau pour chaque sous-région marine. La présente étude s’inscrit dans ce contexte et a pour objectif de décrire les principales structures hydrologiques de la colonne d’eau. Sur la base des données existantes et des travaux antérieurs, il s’agit de classer les masses d'eau en fonction de critères physiques (température, salinité, turbidité, stratification), reconnus d’intérêt pour les espèces pélagiques et l’écosystème en général, et ainsi de définir une cartographie de l’habitat pélagique moyen. Les données utilisées correspondent... |
| Tipo: Text |
Palavras-chave: DCSMM; Habitat pélagique; Classification; Indices hydrologiques; Distribution des espèces; KeywordsMSFD; Pelagic Habitat; Clustering; Hydrological indices; Species distribution. |
| Ano: 2012 |
URL: http://archimer.ifremer.fr/doc/00069/18018/15547.pdf |
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| Le Gac, Pierre-yves; Roux, Gerard; Davies, Peter; Fayolle, Bruno; Verdu, Jacques. |
| Water sorption has been studied gravimetrically for polychloroprene rubber samples, first at a fixed hygrometric ratio (98% HR) and several temperatures (25, 40, 60 and 80°C) for samples of 1.9 and 3.8 mm thickness (Constant Temperature and Hygrometry, CTH experiments), then at fixed temperature (40°C) and several hygrometric ratios ranging from 0 to 95% HR on samples of 0.1 mm thickness (DVS experiments). CTH experiments reveal an abnormal sorption behavior: after an apparently fickian transient period, the water absorption continues at almost constant rate, no equilibrium is observed after more than 2500 hours, whatever the temperature. DVS experiments reveal a very low Henry’s solubility but the formation of clusters at water activities higher than 40%.... |
| Tipo: Text |
Palavras-chave: Polychloroprene; Water sorption; Clustering. |
| Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00188/29903/28350.pdf |
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| Giraud, Georges; Lebecque, Annick; Amblard, Corinne; Bord, Cecile; Sulmont-Rosse, Claire; Lefur, Yves. |
| The paradigm of knowledge-based economy states that information asymmetry between consumers and producers will be reduced thanks to information availability and dissemination through the Internet or other media channels. Conversely to this statement, some published articles shown that knowledge-based economy reinforces the information asymmetry between experts and novices among the consumers (Hogg et al., 2007; Gregan-Paxton & Roedder-John, 1997; Alba & Hutchinson, 1987). Accordingly, we will consider the non homogeneity of consumers and will try to identify and qualify the differences between several groups of respondents regarding two food items by means of a k-means clustering applied to a knowledge-oriented questionnaire. |
| Tipo: Conference Paper or Presentation |
Palavras-chave: Consumer Knowledge; Clustering; Wine; Cheese; France; Agribusiness; Agricultural and Food Policy; Farm Management; Food Consumption/Nutrition/Food Safety; Industrial Organization. |
| Ano: 2008 |
URL: http://purl.umn.edu/49848 |
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| Axalan, Jerick T.; Murray-Prior, Roy B.; Concepcion, Sylvia B.; Lamban, Ruby Jane G.; Real, Rodel R.; Montiflor, Marilou O.; Batt, Peter J.; Rola-Rubzen, Maria Fay; Bacus, Recarte H.; Israel, Floro T.; Apara, Dante A.. |
| Effective relationship among partners is a key in strengthening collaborative marketing efforts. One of the collaborative marketing efforts is through clustering of farmer to link into market. This study examined the level of relationship of vegetable cluster farmers with their market intermediaries - cluster and the downstream buyers. A total of 81 vegetables farmers in Southern Philippines were surveyed to determine their relationship level on trust, power-dependence, relationship-specific investments and satisfaction. Comparison between clusters and downstream buyers were made using ANOVA and Welch Test. The study found that farmers have high level of trust to their clusters compared to their downstream buyers. The high level of trust is attributed to... |
| Tipo: Presentation |
Palavras-chave: Trust; Relationships; Vegetable; Clustering; Southern Philippines; Marketing. |
| Ano: 2012 |
URL: http://purl.umn.edu/124222 |
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| Osei, Edward. |
| Alternative manure application rates represent an integral part of current nutrient management efforts on animal feeding operations (AFOs). Previous studies have indicated that lower manure application rates tend to increase farm production costs. In this study, the Comprehensive Economic and Environmental Optimization Tool - Macro Modeling System (CEEOT-MMS) was used to evaluate the farm-level economic implications of alternative manure application rates for all AFOs in the 48 contiguous states of the U.S. Representative farms derived through statistical disaggregation of national databases and K-means clustering were simulated within the the Farm-level Economic Model (FEM) to determine the economic impacts of four manure application rates. The highest... |
| Tipo: Conference Paper or Presentation |
Palavras-chave: FEM; CEEOT-MMS; Animal feeding operations; Clustering; Costs; Manure; Phosphorus; Crop Production/Industries. |
| Ano: 2008 |
URL: http://purl.umn.edu/6240 |
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| Registros recuperados: 33 | |
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