1000 resultados para forest machines
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Banco del conocimiento
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Changes in the configuration of a tree stern result insignificant differences in its total volume and in the proportion of that volume that is merchantable timber. Tree allometry, as represented by stem-fo~, is the result of the vertical force of gravity and the horizontal force of wind. The effect of wind force is demonstrated in the relationship between stem-form, standclosure and site-conditions. An increase in wind force on the individual tree due to a decrease in stand density should produce a more tapered tree. The density of the stand is determined by the conditions that the trees are growing under. The ability of the tree to respond to increased wind force may also be a function of these conditions . This stem-form/stand-closure/site-conditions relationship was examined using a pre-existing database from westcentral Alberta. This database consisted of environmental, vegetation, soils and timber data covering a wide range of sites. There were 653 sample trees with 82 variables that formed the basis of the analysis. There were eight tree species consisting of Pinus contorta, Picea mariana, Picea engelmannii x glauca, Abies lasiocarpa, Larix laricina, Populus tremuloides, Betula papyrifera and Populus balsamifera plus a comprehensive all-species data set. As the actual conformation of the stern is very individual, stem-fo~was represented by the diameter at breast height to total height r~tio. The four stand-closure variables, crown closure, total basal area, total volume and total number of stems were reduced to total basal area and total number of stems utilizing a bivariate correlation matrix by species. Site-conditions were subdivided into macro, meso and micro variables and reduced in number 3 using cross-tabulations, bivariate correlation and principal components analysis as screening tools. The stem-fo~/stand-closure relationship was examined using bivariate correlation coefficients for stem-fo~ with total number of stems and stem-fo~ with total basal area. The stem-fo~/site-conditions and the stand-closure/site- conditions relationships were examined using multiple correlation coefficients. The stem-form/stand-closure/site-conditions relationship was examined using multiple correlation coefficients in separate analyses for both total number of stems and total basal area. An increase in stand-closure produced a decrease in stem-form for both total number of stems and total basal area for most species. There was a significant relationship between stem-form and site-conditions and between stand-closure and site-conditions for both total number of stems and total basal area for most species. There was a significant relationship between the stemform and site-conditions, including the stand-closure, for most species; total number of stems was involved independently of the site-conditions in the prediction of stem-form and total basal area was not. Larix laricina and Betula papyrifera were the exceptions to the trends observed with most species. The influence of both stand-closure (total number of stems in particular) and site-conditions (elevation in particular) suggest that forest management practices should include these- ecological parameters in determining appropriate restocking levels.
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Chapman Family burial plot, Forest Lawn, Glendale, California. "La Carita" statue.
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It has been well documented, within the field of landscape ecology, that terrestrial fragmentation contributes to increased heterogeneity at the landscape level. It has also been observed that elevated areas of edge habitat occur within fragmented landscapes. Spatial and temporal edge effects were investigated in four areas designated as Nature Reserve Zones within Short Hills Provincial Park, near St. Catharines, Ontario. Random sampling along exposed edges was performed on trees and saplings, at 5 and 25 ill edge depths, using the point-centred quarter method. Diameter at breast height (dbh) and distance from point measurements were used to establish relative density, dominance, frequency and importance value. One-way analyses of variance were used on dbh measurements of tree species and Chi-Square contingency tables were used on size class distributions of saplings species to determine significant differences between 5 and 25 metres. Qualitative comparisons of importance values were also used to determine differences between 5 and 25 metres as well as between trees and saplings. These statistical and qualitative comparisons suggest that a significant overall spatial edge effect is currently exhibited by fragmented wooded islands within the park. The major species of the park, Acersaccharuln, may be exhibiting a temporal edge effect. The heterogeneous nature of the park may be of importance in understanding this area as a complex, ecological system. It is possible that the remaining forest tracts of the park have been affected, and continue to be affected by previous disturbances. Based on these findings, recommendations are made to the Ontario Ministry of Natural Resources concerning the management of Short Hills Provincial Park in accordance with their 1990 proposed Management Plan.
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Bioinformatics applies computers to problems in molecular biology. Previous research has not addressed edit metric decoders. Decoders for quaternary edit metric codes are finding use in bioinformatics problems with applications to DNA. By using side effect machines we hope to be able to provide efficient decoding algorithms for this open problem. Two ideas for decoding algorithms are presented and examined. Both decoders use Side Effect Machines(SEMs) which are generalizations of finite state automata. Single Classifier Machines(SCMs) use a single side effect machine to classify all words within a code. Locking Side Effect Machines(LSEMs) use multiple side effect machines to create a tree structure of subclassification. The goal is to examine these techniques and provide new decoders for existing codes. Presented are ideas for best practices for the creation of these two types of new edit metric decoders.
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Understanding the machinery of gene regulation to control gene expression has been one of the main focuses of bioinformaticians for years. We use a multi-objective genetic algorithm to evolve a specialized version of side effect machines for degenerate motif discovery. We compare some suggested objectives for the motifs they find, test different multi-objective scoring schemes and probabilistic models for the background sequence models and report our results on a synthetic dataset and some biological benchmarking suites. We conclude with a comparison of our algorithm with some widely used motif discovery algorithms in the literature and suggest future directions for research in this area.
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A retrospective article written by Dorothy Rungeling as she recalls the the International Air Races that often began or ended in Welland-Port Colborne Airport. The article was published in the Welland Evening Tribune, 9 September 1977.
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The Ontario Forest Industries Association (OFIA) was founded in 1944. It is a provincial trade association that represents member companies who produce a wide range of products, including pulp, paper, paperboard, lumber, panelboard, plywood and veneer. The OFIA works with its member companies to address issues of common interest and concern, and communicates these issues to the appropriate government, industrial or business sector. The Ontario Forest Information Service represented the OFIA from 1951 to 1988 as the publishers of their industry periodicals. Bush News was the first periodical published by the Service for the OFIA and ran until 1964, when it was replaced by Ontario Logger. In 1968, the name was changed to The Logger. In 1970, this was replaced by The Forest Scene. This new periodical was a departure from the earlier versions, which had served primarily as an internal communication system for the industry. The Forest Scene adopted a new format and editorial approach, emphasizing outdoor activities, recreation, hunting and fishing, conservation, and forestry operations and methods, thus appealing to a much wider readership. The Forest Scene ceased publication in 1988.
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The Brazilian Amazon is one of the world’s largest tropical forests. It supplies more than 80 % of Brazil’s timber production and makes this nation the second largest producer of tropical wood. The forestry sector is of major importance in terms of economic production and employment creation. However, the Brazilian Amazon is also known for its high deforestation rate and for its rather unsustainably managed timber resources, a fact which puts in the balance the long-term future of the forestry sector in the region. Since the mid- 1990s, with strong support from World Wildlife Fund (WWF), the number of tropical forests certified by the Forest Stewardship Council (FSC) has significantly increased. This is especially true for projects sponsored by large scale companies. The number of community- based forest management projects has also increased. Certification of community-based forest enterprises (CFEs) was initially a goal for the sponsors and community members. Certification is viewed as a way to reach alternative timber markets. In Brazil, the state of Acre has the highest concentration of CFEs certified by FSC. Most of them have been implemented with the support of environmental NGOs and public funds. Environmental NGOs strongly defend the advantages of certification for communities; however, in reality, this option is not that advantageous. Despite all the efforts, the number of participants in each project remains low. Why is this occurring? In this paper, we analyze the underlying motives of a few individual’s participation in CFEs certification projects. We aim to present and discuss some factors that shape the success of CFEs and their later certification. The results are based on surveys conducted in two certified CFEs in the state of Acre.
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Notre thèse s’attache à définir certains rapports possibles entre le cinéma et le politique ou, plus précisément, entre le cinéma et le concept pratique de résistance. Il existe une théorie de la résistance, soit sous la forme d’une cartographie du pouvoir moléculaire (M. Foucault), soit sous la forme d’une analytique de la résistance (F. Proust). Il existe également une théorie de la résistance cinématographique, soit comme sociologie ou histoire de l’action politique par le cinéma (cinéma de la Résistance, cinéma militant), soit comme une sémiotique des formes et des genres marginaux (cinéma expérimental, cinéma des avant-gardes). Suivant une direction tracée par Serge Daney et Gilles Deleuze, nous croyons qu’il faut poser autrement le problème : si « le politique est affaire de perception », alors la résistance est d’abord une invention de visibilité et d’audibilité. En ce sens, la résistance cinématographique est une exploration de ce que peut le cinéma, tant d’un point de vue esthétique, éthique, que politique. D’où notre hypothèse, qui est double : d’une part, cette invention de visibilité, cette création de potentiel n’est peut-être possible qu’en passant par un ré-enchaînement anachronique d’une déformation plastique, narrative et audiovisuelle à une autre, c’est-à-dire d’une survivance à une autre. D’autre part, nous croyons qu’une forme esthétique est en soi matière politique et manière de politique, et qu’elle implique également une éthique venant brasser notre propre subjectivité (de cinéaste, de spectateur, de citoyen, etc.). Or, pour saisir cette invention de visibilité inhérente au cinéma, il faut en passer par une généalogie de certaines alliances théoriques et pratiques parmi les plus importantes. Le cas de trois machines autopoïétiques nous intéressera tout particulièrement, trois constellations d’œuvres et de pensées qui débordent le nom propre des « Auteurs » convoqués : Eisenstein et les résistances méthodologiques ; Syberberg et les résistances plastiques ou audiovisuelles (à travers la seule figure du hors-champ) ; Welles et les résistances esth/éthico-politiques. Ainsi, une telle chaîne généalogique nous permettra de mieux mesurer l’efficace de ces résistances, mais sans désir de systématisation ni constitution d’une Théorie de la résistance cinématographique.