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Articles de revues sur le sujet « Tree risk »
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1
Li, Haibin, Xiaowei Zhang, Zeqing Li, Jian Wen et Xu Tan. « A Review of Research on Tree Risk Assessment Methods ». Forests 13, no 10 (23 septembre 2022) : 1556. http://dx.doi.org/10.3390/f13101556.
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As an important part of the urban environment, trees have certain risks while living in harmony with humans. For example, the failure of trees in extreme weather may cause casualties and damage to public and private; the decline and death of old and valuable trees can have an impact on the diversity and cultural value of trees. This paper outlines the theories related to tree risk and the development of tree risk assessment, evaluates the advantages and disadvantages of various tree risk assessment methods in existing studies, and explains some factors affecting the bearing capacity and related applications using knowledge of tree mechanics. Approaches in modern probing techniques are applied to study the response and loading of tree crowns and branches under wind loads, the application of different non-destructive testing techniques in visual assessment for detecting internal defects and root distribution of trees, and the role and impact of objective quantitative test results on tree risk assessment. Finally, the future development direction of tree risk assessment is predicted, which provides an important reference for research on tree risk assessment.
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Browell, Mike F. « TREE RISK ASSESSMENT ». Arboricultural Journal 20, no 1 (février 1996) : 3–12. http://dx.doi.org/10.1080/03071375.1996.9747094.
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Hanum, S. F., I. D. P. Darma, M. B. Atmaja et G. E. A. Oktavia. « Tree Risk Assessment with Sonic Tomograph Method at Bali Botanical Garden ». Jurnal Manajemen Hutan Tropika (Journal of Tropical Forest Management) 26, no 3 (12 décembre 2020) : 233–43. http://dx.doi.org/10.7226/jtfm.26.3.233.
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Safety perception is the most important part of people's choice in determining tourist sites. Standing trees that are prone to falling are very dangerous for both visitors and employees. Standing tree with decay wood inside is often the cause of tree failure. Therefore, there is a need for research examining the risk of collection and non-collection trees in Bali Botanical Garden. Tree risk checks were carried out using the Tree Risk Assessment method from the International Society of Arboriculture (ISA), which has been modified. The result of this research gives valuable information for the manager to determine tree handling to minimize tree risk.
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Walker, Mathew, et Gregory Dahle. « Likelihood of Failure of Trees Along Electrical Utility Rights-of-Way : A Literature Review ». Arboriculture & ; Urban Forestry 48, no 4 (1 juillet 2022) : 242–57. http://dx.doi.org/10.48044/jauf.2022.018.
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Utility vegetation managers need tools to predict tree-related risks and knowledge of the necessary management prescriptions to reduce the risk of windthrow damage to utilities’ electrical infrastructure. This review focuses on key studies involving the likelihood of failure of trees, beginning with a description and discussion of failure in trees, followed by an examination of methodologies that have been used to assess tree failure, before concluding with a review of factors which have been found to influence tree failure. Ultimately, a better understanding of the likelihood of failure of individual trees and the relationships governing tree failure and vegetation-related outages may allow for significant advances in the risk management of utility infrastructure.
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Judice, Abbie, Jason Gordon, Jesse Abrams et Kris Irwin. « Community Perceptions of Tree Risk and Management ». Land 10, no 10 (16 octobre 2021) : 1096. http://dx.doi.org/10.3390/land10101096.
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Urban forests (trees growing in urban and peri-urban areas, including villages and large cities) are vital to mitigating the effects of climate change and urbanization but require special considerations such as risk mitigation in developed landscapes. Despite abundant research on risk perceptions of natural hazards, there is limited knowledge about risk perceptions associated with urban trees. As such, this research examines community perceptions of urban tree risk mitigation with a focus on four cities in the U.S. south. To better understand risk perceptions and mitigation, this study employs key informant interviews with community members. Guided by a socio-ecological resilience framework, the findings identify factors affecting resident attitudes towards tree management on the individual parcel and the community levels. The findings benefit tree risk governance in the face of climate variability, which increases societal and environmental vulnerability in urban settings.
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Hart, Keiron. « Tree risk assessment manual ». Arboricultural Journal 36, no 3 (3 juillet 2014) : 179–80. http://dx.doi.org/10.1080/03071375.2014.930244.
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Bakken, Stephen. « Group-Tree Hazard Analysis ». Arboriculture & ; Urban Forestry 21, no 3 (1 mai 1995) : 150–55. http://dx.doi.org/10.48044/jauf.1995.025.
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Tree hazard control programs focus on individual tree risk analysis. Although microsite conditions are often evaluated, whole forests or groups of trees are rarely considered. A tree hazard program was initiated at a northern California state park in 1969. Since then, hundreds of trees have been removed from the campground to reduce the agency's liability. Nevertheless, hundreds more trees have failed, causing injury and property damage. Traditional single tree risk assessment proved to be inadequate to stabilize this forest. Consequently, the environmental dynamics of the entire forest were assessed, and every tree was evaluated for its positive or negative contribution to the long term stability of the forest.
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Suchocka, Marzena, Tatiana Swoczyna, Joanna Kosno-Jończy et Hazem M. Kalaji. « Impact of heavy pruning on development and photosynthesis of Tilia cordata Mill. trees ». PLOS ONE 16, no 8 (23 août 2021) : e0256465. http://dx.doi.org/10.1371/journal.pone.0256465.
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Tree pruning is carried out to reduce conflict with infrastructure, buildings, and any other human activity. However, heavy pruning may result in a diminished tree crown capacity for sugar production and exposure to fungal infection. This risk leads to a decrease in tree stability or vigour. In this work, we analysed the effect of heavy pruning of roadside trees on the photosynthetic performance process compared to neighbouring unpruned trees. Four years of tree crown growth was studied by terrestrial imaging. Tree vitality (Roloff’s classification) and risk (Visual Tree Assessment) were evaluated. Over-pruned trees showed intensified photosynthetic efficiency during the growing season following pruning. Particularly ET0/TR0 and PIABS tended to increase in pruned trees while higher Fv/Fm was noted only in late October, suggesting delayed leaf senescence. After four years, pruned trees rebuilt their crowns, however not in their entirety. Results obtained from biometric, vitality, and risk assessment showed high differentiation in pruned tree crown recovery. Our results revealed that despite the intensified efforts of trees to recover from wounding effects, severe pruning evokes dieback occurrence and a higher risk of failure in mature trees.
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Sreetheran, M., M. Adnan et A. K. Khairil Azuar. « Street Tree Inventory and Tree Risk Assessment of Selected Major Roads in Kuala Lumpur, Malaysia ». Arboriculture & ; Urban Forestry 37, no 5 (1 septembre 2011) : 226–35. http://dx.doi.org/10.48044/jauf.2011.030.
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Tree planting programs in Malaysia have progressed as planned. However, the subsequent management of the street trees, particularly at Kuala Lumpur City Hall, is not well undertaken due to inadequate information for management and maintenance purposes. There has never been a systematic tree survey conducted to inventory street trees in Kuala Lumpur. With this, a survey was conducted to collect comprehensive information on tree structure, species composition, species diversity, and tree defects and disorders. A total 2,191 street trees were surveyed.
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Guggenmoos, Siegfried. « Effects of Tree Mortality on Power Line Security ». Arboriculture & ; Urban Forestry 29, no 4 (1 juillet 2003) : 181–96. http://dx.doi.org/10.48044/jauf.2003.022.
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Others have reported that instances where trees grow into lines rarely result in power outages. The vast majority of tree-related outages stem from tree failure, particularly if outages during severe weather events are included. Generally, treeconductor conflicts resulting from tree failure are classified as unpreventable because the trees are located outside the right-of-way. In the emerging competitive environment, utilities will require a means of decreasing so-called unpreventable outages. The primary locations for unpreventable outages are areas where lines run adjacent to or through natural forest tree stands. Tree mortality exposes a power line to a high risk of tree incidents over time. The risk to the line is directly related to the number of trees within striking distance of the line. Conventional clear widths leave a substantial residual tree risk. Hazard tree removal programs do not provide enduring reliability gains. A new mathematical model, the optimal clear width calculator, is used to assess the tree risk over variable clear widths and line heights. The risk ratings in the output line strike probability charts permit quantitative comparisons of construction and maintenance options. The line strike probability chart indicates that there is a point of diminishing return in line security for dollars invested in additional clear width.
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Duntemann, Mark. « ELEMENTS OF AN URBAN TREE RISK MANAGEMENT PROGRAM ». Revista da Sociedade Brasileira de Arborização Urbana 1, no 1 (10 décembre 2006) : 99. http://dx.doi.org/10.5380/revsbau.v1i1.66503.
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The development of effective hazard trees assessment practices has been an important focus of urban forestry for many years. When a publicly owned tree fails and causes property damage, personal injury or death in the United States, a potential consequence for a government agency is litigation. Although managing a large public tree resource can seem daunting, simple assessment parameters can be used to identify high-risk features within the tree population. Through analysis of the interaction between high-risk elements in the tree population and definition of a long-term, managed approach to tree risk reduction, strong policies and practices can be initiated. This program emphasizes two concepts. First, implementation of a well thought out risk reduction strategy improves the overall health of the urban forest, which results in a safer urban environment. This goal is universal, regardless of national boundaries. Second, documentation and implementation of tree risk management policies forms the foundation for a government agency’s defense, if litigation ever occurred.
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Malík, V., et J. Stuchlý. « Risk factors influencing the probability of browsing by hoofed game on forest trees ». Journal of Forest Science 53, No. 8 (7 janvier 2008) : 359–63. http://dx.doi.org/10.17221/2179-jfs.
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In this paper we analyze how selected risk factors determine the probability of browsing by hoofed game on forest trees. Risk factors covered by the model are: tree species (Norway spruce or Scotch pine), time period (season: spring + summer or autumn + winter) and chemical structure of bark (content of selected nutrients and chemical elements). We use a logit model for these purposes. We formulate the model and perform linear transformation by the natural log. Since the disturbance term in the logit model is heteroscedastic, we cannot use the ordinary least-squares method to estimate the parameters of the model. In this case the maximum likelihood method included in STATGRAPHICS Plus for Windows program is used for its estimation. We use a random sample of data including 59 trees. We do the interpretations of the estimated parameters and other characteristics. We demonstrate how the estimated probabilities depend on the considered factor. The model explains 44.1% of variations of the logits, the model is statistically significant. All regression coefficients are significant at least at 12% confidence level. Among the main explanatory variables (content of P, Ca, NO<sub>3</sub>, tree species and season), the P and Ca contents in the bark of the tree are the most important factors influencing the probability of future damage to the tree.
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Ellison, Michael. « Quantified Tree Risk Assessment used in the Management of Amenity Trees ». Arboriculture & ; Urban Forestry 31, no 2 (1 mars 2005) : 57–65. http://dx.doi.org/10.48044/jauf.2005.007.
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A system of tree risk assessment is proposed that expands concepts developed by others and enables a probability of significant harm to be applied to tree failure risk. By evaluating the components of a tree failure hazard and assigning to them estimates of probability, the proposed system enables the skilled tree inspector to calculate the product of those probabilities to produce a numerical estimate of risk. The use of quantification in the assessment of tree hazards enables property owners and managers to operate, as far as is reasonably practicable, to a predetermined limit of reasonable or acceptable risk.
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Kim, Dong-won, Keun-hee Han, In-seok Jeon et Jin-yung Choi. « Telemedicine Security Risk Evaluation Using Attack Tree ». Journal of the Korea Institute of Information Security and Cryptology 25, no 4 (31 août 2015) : 951–60. http://dx.doi.org/10.13089/jkiisc.2015.25.4.951.
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Guillemette, François, Steve Bédard et Mathieu Fortin. « Evaluation of a tree classification system in relation to mortality risk in Québec northern hardwoods ». Forestry Chronicle 84, no 6 (1 décembre 2008) : 886–99. http://dx.doi.org/10.5558/tfc84886-6.
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A tree classification system was developed in the 1980s as part of a guide for tree-marking in the rehabilitation of unevenaged northern hardwood stands in Québec. It differentiates trees that are at high and low risk of mortality, trees with sawlog potential and cull trees. The risk class was assessed based on the presence of major crown and bole defects. The main objective of the present study was to evaluate this system with respect to its capacity to predict the probability of tree mortality. The variables used to classify the trees were observed in 88 experimental plots (0.5 ha) established between 1983 and 1999. Tree-level mortality probabilities were modelled for sugar maple (Acer saccharum Marsh.), American beech (Fagus grandifolia Ehrh.) and yellow birch (Betula alleghaniensis Britt.) to test the significance of the classification variables. The presence of decay, fungus or canker, wounds, uprooting, the death of at least 30% of the crown or of the roots, and the product class had significant (p < 0.05) effects on mortality probabilities for at least one of the 3 species studied. In the main, the results supported the tree classification system. However, this system could be modified to differentiate not only trees with a high or low mortality risk, but also to identify some very high-risk trees. Key words: northern hardwood, mortality, defect, quality, classification, selection cutting, partial cut, sugar maple, American beech, yellow birch, uneven-aged, tree-marking
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Helmanto, H., F. Damayanti et A. N. Rachmadiyanto. « A safety factor of old trees Pterocarpus indicus Willd. in Bogor Botanic Gardens ». IOP Conference Series : Earth and Environmental Science 950, no 1 (1 janvier 2022) : 012009. http://dx.doi.org/10.1088/1755-1315/950/1/012009.
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Abstract Trees have a vital role in human life, including as a part of the urban forest area. The tree health assessment is an important activity to support tree safety and stability in an urban forest. Bogor Botanic Garden is the most extensive botanic garden in Indonesia, with a large collection. The study aims to determine the health condition of old trees (Pterocarpus indicus Willd.) in the Bogor Botanic Gardens and measure the safety factor’s magnitude. The method used was an evaluation generated based on a sound velocity from Arborsonic’s tool. The measurement of appearance parameters was carried out to complete the information in determining the biomechanical strength of the tree. Four large and old trees, about 170 years old, were chosen in this study. The results showed that decay to hollowness in the trunk varied from 4% to 58%. The biomechanical analysis calculates the safety factor and t/R ratio, revealing that one tree had moderate risk and others possessed low risk. Further investigation to ensure the tree condition should be carried in terms of risk mitigation of tree management.
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Rust, Steffen, et Bernhard Stoinski. « Using Artificial Intelligence to Assist Tree Risk Assessment ». Arboriculture & ; Urban Forestry 48, no 2 (1 mars 2022) : 138–46. http://dx.doi.org/10.48044/jauf.2022.011.
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Although the industry has raised the standards of tree risk assessment considerably in recent years, the quality of judgements is still very variable and influenced by a wide range of factors. Due to the complexity and diversity of trees and sites, collecting and verifying relevant personal experiences takes tree assessors many years. In many countries, new tree assessors learn from a small number of experienced peers. Artificial intelligence (AI) can be used to collect and condense scattered knowledge and deploy it in a support tool for basic tree assessment. In this project, the application of a commercial AI decision-making system software (Dylogos) to tree assessment is tested. The software is based on a new dynamic nonclassical logic, which combines diverse knowledge sources to an emergent system to support visual tree assessments. A set of rules describes existing knowledge about the mostly unsharp parameters affecting the likelihood of failure and damage. The software evaluates the data collected during a basic tree assessment and provides an estimate of the level of risk posed by the tree. The result and the reasons for it are presented in plain language. Users can then examine this estimate and feed their own assessment back into the system to train it further, so that this “white” AI system is self-learning based on experience acquired in practical use. The use of AI in tree risk assessment not only supports the user but can also be used to disseminate knowledge and promote the standardization of decision-making in tree assessment. Important directions for further research and knowledge gaps related to the training of AI systems in the absence of industry-wide, agreed-upon criteria for risk identified in this project are: how to collect sufficient quality-assured data sets to define the initial set of rules; and how to assess the level of expertise of users training the system further.
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Kane, Brian, Michael Pavlis, J. Roger Harris et John R. Seiler. « Crown reconfiguration and trunk stress in deciduous trees ». Canadian Journal of Forest Research 38, no 6 (juin 2008) : 1275–89. http://dx.doi.org/10.1139/x07-225.
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In light of the risk of litigation following damage related to tree failure in urban and suburban settings, more empirical data related to tree risk assessment are needed. We measured drag and drag-induced bending moment (M) and calculated drag coefficient (CD) and trunk stress (σ) for three deciduous trees at wind speeds up to 22.4 m/s. We measured the modulus of rupture (MOR) of wood samples from trunks and calculated the factor of safety (SF = MOR / σ) for each tree. We also investigated which tree morphometric variables best predicted drag and M and whether simple two- and three-dimensional shapes accurately represented actual tree crowns. Drag, CD, M, σ, and SF differed among species in accordance with physical parameters. More massive trees experienced greater drag and M, but σ was greater for trees with smaller trunk diameters. Tree mass reliably predicted drag and M; crown dimensions, including crown area, were less reliable predictors. Crown reconfiguration varied only slightly among species, and CD values were similar to previously reported values for trees of similar size. Our study has important applications for practitioners who manage tree risk, particularly the critical wind speeds and percentage of trunk cross-sectional area that could be decayed before trunk failure.
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Hanum, S. F., I. D. P. Darma, M. B. Atmaja, G. A. E. Oktavia, H. Merriansyah et A. Fauzi. « Tree slenderness coefficient at Bali Botanic Garden ». IOP Conference Series : Earth and Environmental Science 918, no 1 (1 novembre 2021) : 012038. http://dx.doi.org/10.1088/1755-1315/918/1/012038.
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Abstract Standing trees has a higher risk regarding structural damage that can cause trees or parts of trees to fail. Meanwhile, Bali Botanic Garden is located in a highland area that periodically gets natural disasters such as heavy wind. However, the information on tree stability is little known. Therefore, tree stability at Bali Botanic Garden was assessed using tree slenderness coefficient (SC) as an indicator. Purposive sampling technique was adopted for locations which highly visited. A total of 624 trees with dbh>40 cm were examined as samples. Trees were classified based on their SC as high (>80), moderate (SC:70-80), low (SC<70). Data were analyzed using descriptive and correlation analysis. Tree slenderness coefficient at Bali Botanic Garden classified as low (609 specimens), medium (11 specimens), and high (4 specimens). Trees with the high category were three individuals of Bischofia javanica Blume (SC=82.76, 83.69, and 89.63) and a Syzygium polyanthum (Wight) Walp. (SC=116.13). Trees with high SC had a higher susceptibility to wind-induced damage. There was a negative correlation between SC and others tree parameters except for tree height (r=0.44). Hence appropriate silvicultural treatment like thinning is recommended to enhance better tree development and minimize tree risk.
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Trinh, Yen Thuan, et Bernard Hanzon. « An introduction to Monte Carlo-Tree (MC-Tree) method ». Boolean 2022 VI, no 1 (6 décembre 2022) : 94–96. http://dx.doi.org/10.33178/boolean.2022.1.16.
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The article aims to introduce concepts in option pricing and risk management. Pricing and risk management is one of the fundamental problems in financial mathematics. Then readers may explore further to understand how to use mathematical models in pricing and risk management. More specifically, our research introduces a new method called Monte Carlo-Tree (MC-Tree), for option pricing and risk management with high accuracy.
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Sharma, Leena, Kent Kwoh, Jungwha (Julia) Lee, Jane Cauley, Rebecca Jackson, Marc Hochberg, Alison H. Chang et al. « Development and validation of risk stratification trees for incident slow gait speed in persons at high risk for knee osteoarthritis ». Annals of the Rheumatic Diseases 78, no 10 (26 juin 2019) : 1412–19. http://dx.doi.org/10.1136/annrheumdis-2019-215353.
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ObjectivesDisability prevention strategies are more achievable before osteoarthritis disease drives impairment. It is critical to identify high-risk groups, for strategy implementation and trial eligibility. An established measure, gait speed is associated with disability and mortality. We sought to develop and validate risk stratification trees for incident slow gait in persons at high risk for knee osteoarthritis, feasible in community and clinical settings.MethodsOsteoarthritis Initiative (derivation cohort) and Multicenter Osteoarthritis Study (validation cohort) participants at high risk for knee osteoarthritis were included. Outcome was incident slow gait over up to 10-year follow-up. Derivation cohort classification and regression tree analysis identified predictors from easily assessed variables and developed risk stratification models, then applied to the validation cohort. Logistic regression compared risk group predictive values; area under the receiver operating characteristic curves (AUCs) summarised discrimination ability.Results1870 (derivation) and 1279 (validation) persons were included. The most parsimonious tree identified three risk groups, from stratification based on age and WOMAC Function. A 7-risk-group tree also included education, strenuous sport/recreational activity, obesity and depressive symptoms; outcome occurred in 11%, varying 0%–29 % (derivation) and 2%–23 % (validation) depending on risk group. AUCs were comparable in the two cohorts (7-risk-group tree, 0.75, 95% CI 0.72 to 0.78 (derivation); 0.72, 95% CI 0.68 to 0.76 (validation)).ConclusionsIn persons at high risk for knee osteoarthritis, easily acquired data can be used to identify those at high risk of incident functional impairment. Outcome risk varied greatly depending on tree-based risk group membership. These trees can inform individual awareness of risk for impaired function and define eligibility for prevention trials.
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Abuseif, Majed, Karine Dupre et Ruby N. Michael. « Trees on Buildings : A Tree Selection Framework Based on Industry Best Practice ». Land 12, no 1 (28 décembre 2022) : 97. http://dx.doi.org/10.3390/land12010097.
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Trees on buildings have received increased interest, and installations have multiplied over recent years, yet there is limited literature and policies guiding the successful implementation of projects relating to trees on buildings. This study investigates the tree selection process for implementation on buildings, using a survey and follow-up interviews with experienced experts to reveal current worldwide industry best practice, and provides a systematic framework for selecting the most appropriate tree species. A tree selection framework is proposed that consists of four stages: identifying the purpose of the tree; analysing the site context and its conditions; evaluating the risk of implementation; and investigating the characteristics of the candidate trees. Decision-makers can use the developed framework to inform design, implementation, and policy development of trees on buildings to reduce implementation risks. In addition, this paper provides useful insights to inform future research about trees on buildings.
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Ver Planck, Neil R., et David W. MacFarlane. « Branch mass allocation increases wind throw risk for Fagus grandifolia ». Forestry : An International Journal of Forest Research 92, no 4 (6 février 2019) : 490–99. http://dx.doi.org/10.1093/forestry/cpz001.
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Abstract Wind is a major force of disturbance in forests throughout the world, causing trees to break or uproot and topple over, depending on tree morphology and growing conditions. Previous research has suggested that trees that are more massive or which have lower height–diameter ratios are less at risk to wind throw, but the influence of crown size and branching architecture has been more difficult to elucidate. In general, there has been more research on coniferous trees, which have more simplified and symmetrical crown structures, relative to broad-leaved, deciduous trees. Here, we modelled the probability of wind throw for American beech (Fagus grandifolia Ehrh.), a broad-leaved, deciduous species common in the eastern USA, for trees covering a broad range of sizes (5.6–79.8 cm, diameter at breast height), in two nearby stands, in an experimental forest in southwestern Michigan, USA, where a wind event occurred. After a major blow-down of more than 200 trees in one of the stands, a subset of trees was destructively sampled after the storm. Analysis of the characteristics of the wind-thrown versus non-wind-thrown, residual trees, indicated that a very large branch fraction of total tree mass was a key factor leading to toppling of the wind-thrown trees. This study provides new empirical data related to the characteristics of wind-thrown American beech trees and suggests a potentially important role for branch to stem mass ratios as a predictor of wind throw risk for this species and possibly other broad-leaved, deciduous tree species, with a deliquescent branching architecture.
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Roman, Lara A., Jason P. Fristensky, Robert E. Lundgren, Chloe E. Cerwinka et Jason E. Lubar. « Construction and Proactive Management Led to Tree Removals on an Urban College Campus ». Forests 13, no 6 (1 juin 2022) : 871. http://dx.doi.org/10.3390/f13060871.
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Urban trees in lawns and along streets are anthropogenically constructed systems, in that these tree communities are formed by human planting and removal actions. Tree mortality studies are essential to understanding the temporal dynamism of urban forests, and in particular, it is critical to incorporate institutional records and human decision-making regarding tree removals. In this study, we investigated tree removals on a highly urbanized college campus in Philadelphia, Pennsylvania (US) by analyzing field inventories and institutional records, and by considering firsthand accounts of the University Landscape Architect. The annual mortality rate was 4.3%, higher than typical for comparable studies, which we attribute to construction pressure and proactive management to promptly remove unhealthy trees and manage risk. Capital projects and other construction caused 48.5% of all removals, other human land use decisions caused 2.0%, and tree health decline and risk management collectively accounted for 48.7%. The number of removed trees exactly equaled the number of new trees, and the campus has high taxonomic diversity, reflecting the extensive oversight by university tree and landscape professionals regarding tree removal and planting decisions. This study demonstrates the value of mixed-methods and transdisciplinary research to understand how urban forests change over time.
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Pardue, Harold, Jeffrey P. Landry et Alec Yasinsac. « E-Voting Risk Assessment ». International Journal of Information Security and Privacy 5, no 3 (juillet 2011) : 19–35. http://dx.doi.org/10.4018/jisp.2011070102.
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Approximately 25% (according to http://verifiedvoting.com/) of voting jurisdictions use direct recording electronic systems to record votes. Accurate tabulation of voter intent is critical to safeguard this fundamental act of democracy: voting. Electronic voting systems are known to be vulnerable to attack. Assessing risk to these systems requires a systematic treatment and cataloging of threats, vulnerabilities, technologies, controls, and operational environments. This paper presents a threat tree for direct recording electronic (DRE) voting systems. The threat tree is organized as a hierarchy of threat actions, the goal of which is to exploit a system vulnerability in the context of specific technologies, controls, and operational environment. As an abstraction, the threat tree allows the analyst to reason comparatively about threats. A panel of elections officials, security experts, academics, election law attorneys, representatives from governmental agencies, voting equipment vendors, and voting equipment testing labs vetted the DRE threat tree. The authors submit that the DRE threat tree supports both individual and group risk assessment processes and techniques.
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Wan Azulkefeli, Wan Adhwa Ezzdihar Sharfa, Osman Mohd Tahir, Emran@Zahrin Mohamad Taram et Faiza Darkhani. « Reviewing Tree Risk Inventory Model for Tropical Urban Trees by Malaysian Experts ». Environment-Behaviour Proceedings Journal 7, no 19 (31 mars 2022) : 209–15. http://dx.doi.org/10.21834/ebpj.v7i19.3264.
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The study aims to develop a new framework of tree assessment that is suitable for Malaysia’s tropical urban trees. A focus group discussion (FGD) method was conducted with Malaysian experts regarding the criteria needed to assess a tree's condition starting from the juvenile stage. Found that 92% of the participants agree with the preliminary framework presented. Additional components were added to the preliminary framework based on the data collected. The study could increase the relevant organizations' knowledge of managing urban trees and decrease the deterioration and decline of urban trees in Malaysia. Keywords: hazardous trees; tree monitoring; urban forestry, tree assessment eISSN: 2398-4287 © 2022. The Authors. Published for AMER ABRA cE-Bs by e-International Publishing House, Ltd., UK. This is an open access article under the CC BYNC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/). Peer–review under responsibility of AMER (Association of Malaysian Environment-Behaviour Researchers), ABRA (Association of Behavioural Researchers on Asians/Africans/Arabians) and cE-Bs (Centre for Environment-Behaviour Studies), Faculty of Architecture, Planning & Surveying, Universiti Teknologi MARA, Malaysia. DOI: https://doi.org/10.21834/ebpj.v7i19.3264
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Wan Azulkefeli, Wan Adhwa Ezzdihar Sharfa, Emran@Zahrin Mohamad Taram, Hashim Gombri et Faiza Darkhani. « Reviewing Tree Risk Inventory Framework for Tropical Urban Trees by Malaysia Experts ». Environment-Behaviour Proceedings Journal 7, no 21 (30 septembre 2022) : 303–9. http://dx.doi.org/10.21834/ebpj.v7i21.3726.
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Malaysia lost 14.4% of its forests due to deforestation. As a result, the forests' ability to protect against physical disturbances was no longer practical. The study aims to review a framework of tree risk inventory for Malaysia’s tropical urban trees. Some expert interview sessions were conducted with Malaysian experts to present the proposed framework. Found that 100% of the experts agree with the framework presented. Additional components were added to the framework based on the data collected. The study could increase the relevant organizations' knowledge of managing tropical urban trees and decrease the deterioration and decline of tropical urban trees in Malaysia. Keywords: hazardous trees; tree monitoring; urban forestry, tree assessment eISSN: 2398-4287 © 2022. The Authors. Published for AMER ABRA CE-Bs by e-International Publishing House, Ltd., UK. This is an open-access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/). Peer–review under responsibility of AMER (Association of Malaysian Environment-Behaviour Researchers), ABRA (Association of Behavioural Researchers on Asians/Africans/Arabians), and cE-Bs (Centre for Environment-Behaviour Studies), Faculty of Architecture, Planning & Surveying, Universiti Teknologi MARA, Malaysia. DOI: https://doi.org/10.21834/ebpj.v7i21.3726
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Björnsson, Y., et T. A. Marsland. « Risk management in game-tree pruning ». Information Sciences 122, no 1 (janvier 2000) : 23–41. http://dx.doi.org/10.1016/s0020-0255(99)00097-3.
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Lu, Y., A. Mathur, D. Black, T. Fuerst et H. K. Genant. « Survival tree analysis for fracture risk ». Osteoporosis International 6, S1 (janvier 1996) : 126. http://dx.doi.org/10.1007/bf02500044.
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Fay, Neville. « TOWARDS REASONABLE TREE RISK DECISION-MAKING ? » Arboricultural Journal 30, no 2 (octobre 2007) : 143–61. http://dx.doi.org/10.1080/03071375.2007.9747489.
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Rachmadiyanto, A. N., L. Karlinasari, D. Nandika, J. R. Witono et I. Z. Siregar. « Is leaning trees of Vatica pauciflora (Korth.) Blume related to their crown architecture ? » IOP Conference Series : Earth and Environmental Science 918, no 1 (1 novembre 2021) : 012017. http://dx.doi.org/10.1088/1755-1315/918/1/012017.
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Abstract Vatica pauciflora (Korth.) Blume (Dipterocarpaceae) or locally known as resak rawa is an important tree. It is categorized as vulnerable regarding the IUCN (International Union for Conservation of Nature) Red List of Threatened Species. We can find the resak rawa tree collection in the Bogor Botanic Gardens, which serves as a place for research and tourism. Due to the diversity in individual tree anatomy within species, understanding correlation among individual tree traits, particularly crown architecture and tree leaning, is of great interest. That will be important because the leaning trees and crown architecture will affect the risk level to the safety of visitors. We can also use the architecture of the tree crown to understand the factors that influence tree growth. This study aims to investigate the correlation between the leaning trees and the crown architecture of V. pauciflora. Eight heritage trees of the species in the Bogor Botanic Gardens at the age of 54–105 years old were purposely, sampled in this study. The variables observed were height, trunk and crown diameter, leaning tree, live crown ratio, and direction of the main branches. The results show that crown shapes will follow the leaning trees with a correlation of 0.97. The main branches will be longer in the direction of the leaning trees (y=0.9956x+11.312; R²=0.9431). Suggestions to the management of V. pauciflora are to provide information boards to visitors and pruning the crown in the direction of the leaning trees is needed. The findings could be used to formulate mitigation measures as to the risk and safety of visitors.
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van Haaften, Marinus, Yili Liu, Yuxin Wang, Yueyue Zhang, Cornelis Gardebroek, Wim Heijman et Miranda Meuwissen. « Understanding tree failure—A systematic review and meta-analysis ». PLOS ONE 16, no 2 (16 février 2021) : e0246805. http://dx.doi.org/10.1371/journal.pone.0246805.
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Recent research has indicated an increase in the likelihood and impact of tree failure. The potential for trees to fail relates to various biomechanical and physical factors. Strikingly, there seems to be an absence of tree risk assessment methods supported by observations, despite an increasing availability of variables and parameters measured by scientists, arborists and practitioners. Current urban tree risk assessments vary due to differences in experience, training, and personal opinions of assessors. This stresses the need for a more objective method to assess the hazardousness of urban trees. The aim of this study is to provide an overview of factors that influence tree failure including stem failure, root failure and branch failure. A systematic literature review according to the PRISMA guidelines has been performed in databases, supported by backward referencing: 161 articles were reviewed revealing 142 different factors which influenced tree failure. A meta-analysis of effect sizes and p-values was executed on those factors which were associated directly with any type of tree failure. Bayes Factor was calculated to assess the likelihood that the selected factors appear in case of tree failure. Publication bias was analysed visually by funnel plots and results by regression tests. The results provide evidence that the factors Height and Stem weight positively relate to stem failure, followed by Age, DBH, DBH squared times H, and Cubed DBH (DBH3) and Tree weight. Stem weight and Tree weight were found to relate positively to root failure. For branch failure no relating factors were found. We recommend that arborists collect further data on these factors. From this review it can further be concluded that there is no commonly shared understanding, model or function available that considers all factors which can explain the different types of tree failure. This complicates risk estimations that include the failure potential of urban trees.
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Nakada, Setsuya, Fukashi Maeno, Mitsuhiro Yoshimoto, Natsumi Hokanishi, Taketo Shimano, Akhmad Zaennudin et Masato Iguchi. « Eruption Scenarios of Active Volcanoes in Indonesia ». Journal of Disaster Research 14, no 1 (1 février 2019) : 40–50. http://dx.doi.org/10.20965/jdr.2019.p0040.
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Eruption scenarios were prepared as possible sequences in event trees for six active volcanoes in Indonesia, that are located near populated areas or have erupted in recent years (Galunggung, Guntur, Kelud, Merapi, Semeru, and Sinabung). The event trees prepared here show sequences of possible eruption phenomena without probabilities on branches and cover sequences experienced in historical and pre-historical eruptions based on archives and field research results. Changing magma discharge rates during eruption sequences were considered for the event tree of Merapi. This conceptual event tree can also be used as a short-term event tree in which forecasting the coming eruption became possible with geophysical and geochemical monitoring data. Eruption event trees prepared for selected time windows cannot illustrate all plausible hazards and risks associated with an eruption. Therefore, hazards and risks generated from an eruption should be considered in different domains from the event tree.
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Shan, Rui, Xianfei Xiao, Junwen Che, Jingfang Du et Yuwu Li. « Data Mining Optimization Software and Its Application in Financial Audit Data Analysis ». Mobile Information Systems 2022 (13 juillet 2022) : 1–7. http://dx.doi.org/10.1155/2022/6851616.
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The scope of finance is very wide, data also plays a very important role in the financial industry, a small data change, and it may have a great impact on the economy. Therefore, the author proposes data mining optimization software and its application in financial audit data analysis. First, discuss the decision tree method, the main function module design of the system software, the financial analysis software method of weighted multiple random decision trees is described. To conduct verification experiments, the decision-making effect of constructing 10 random decision trees is the best. So, the author constructed a total of 10 random decision trees to analyze the data, since the tree is constructed using a random method, in order to verify the stability of decision tree classification, a total of 5 experiments were carried out, the training data set for each experiment, randomly select 1200 pieces of data from the original data set as training data, the tree is constructed by randomly selecting 12 attributes from 24 attributes. The remaining 300 pieces of data are used as verification data. As can be seen from the results, the accuracy of the random decision tree method is about 10% higher than that of C4.5. In order to improve the accuracy rate of high risk, 300 pieces of high-risk data were added to the training data set. To change the original random sampling into stratified sampling, according to the high, medium, and low risk, the original data is stratified; random sampling is used for each layer, thereby ensuring the amount of training data with high risk. The accuracy of decision tree classification is related to the number of samples of the training data, the larger the number of samples, the more accurate the classification of the constructed decision tree.
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Xie, Gang, Dazhi Xue et Shuren Xi. « TREE-EXPERT : a tree-based expert system for fault tree construction ». Reliability Engineering & ; System Safety 40, no 3 (janvier 1993) : 295–309. http://dx.doi.org/10.1016/0951-8320(93)90066-8.
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Chan, Woei Leong, Yongdong Cui, Siddharth Sunil Jadhav, Boo Cheong Khoo, Heow Pueh Lee, Chi Wan Calvin Lim, Like Gobeawan et al. « Experimental study of wind load on tree using scaled fractal tree model ». International Journal of Modern Physics B 34, no 14n16 (10 avril 2020) : 2040087. http://dx.doi.org/10.1142/s0217979220400871.
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Green urbanism has stimulated more research on the aerodynamics of tree in recent years. The insight gained in studying wind load on trees would mitigate risk of tree falling and enable sustainable landscape planning. However, deciphering the effect of wind on trees is a daunting task because trees come in various species, shapes and sizes. In this study, we aim at conducting wind tunnel tests on various species of trees, including measuring the respective drag coefficient and turbulent flow field using a force balance and particle image velocimetry system. The wind tunnel experiment is conducted using scaled down fractal tree model at 10 and 15 m/s. The 3D-printed tree model is grown based on the data collected on the species-specific tree parameters, such as the height, trunk diameters, crown box dimensions, etc. In this paper, the wind tunnel result of Yellow Flame (Peltophorum pterocarpum) is presented. Results show that the drag coefficient for this inflexible tree model is not sensitive to wind speed. The Reynolds shear stress and turbulence kinetic energy are observed to be the largest at the top and bottom of the crown where the velocity gradients are the highest.
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Paine, T. D., M. K. Malinoski et G. T. Scriven. « Rating Eucalyptus vigor and the risk of insect infestation : leaf surface area and sapwood:heartwood ratio ». Canadian Journal of Forest Research 20, no 9 (1 septembre 1990) : 1485–89. http://dx.doi.org/10.1139/x90-196.
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Phoracanthasemipunctata (Fab.) colonizes and kills stressed Eucalyptus spp. in both managed and unmanaged stands in southern California. Stressed trees frequently manifest thinner crowns, with less foliage surface area, than more vigorous trees. This is reflected in reduced conducting sapwood and a lower sapwood:heartwood ratio. Four species of Eucalyptus at four sites were examined, and correlation analyses of leaf surface area to sapwood area were conducted. Using E. cladocalyx as a model, trees in a stand suffering high tree mortality showed significantly lower sapwood:heartwood ratios than trees in stands with beetle activity restricted to dead limbs but evincing little tree mortality. This index could be utilized to identify high-risk stands for implementation of silvicultural management practices.
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Martiansyah, Irfan, Rizmoon Nurul Zulkarnaen, Muhammad Rifqi Hariri, Prima Wahyu Kusuma Hutabarat et Fitri Fatma Wardani. « Tree Health Monitoring of Risky Trees in the Hotel Open Space : A Case Study in Rancamaya, Bogor ». Jurnal Sylva Lestari 10, no 2 (14 mars 2022) : 180–201. http://dx.doi.org/10.23960/jsl.v10i2.570.
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Tree health monitoring of risky trees is necessary, especially in areas with a high level of accessibility, such as in hotels and tourist areas. The increased accessibility of hotel visitors and the green space require increased awareness of the risk of falling trees. This research aimed to estimate the amount of internal decay and damage of living trees, with special attention to the large tree in the open space of R Hotel Rancamaya. Tree health monitoring was carried out using two approaches, namely visual observation Sonic Tomography method. The visual parameters were observed following the standard method of the International Society of Arboriculture. A total of 8 trees consists of four types of plants such as Melia azedarach, Durio zibethinus, Falcataria falcata, and Ficus subcordata. The eight trees visually showed no significant damage to their organs. The results of internal trunk inspection by PiCUS-3 Sonic Tomograph also showed a similar result with decay or weathering ranges ranging from 1-3% in healthy trees, except for the stem base of tree 7 (M. azedarach) with weathering of 18%. Handling that needs to be done on six trees at the green area hotel is through light pruning and installing warning signs so that visitors and staff are careful in the tree area. Substantial pruning is recommended specifically for tree 7 because there is significant weathering, and it could be dangerous if the tree is not appropriately handled. The assessment showed that mitigation, warning signs, and physical handling are essential to prevent any unpredicted fallen trees, especially for tree 3 (D. zibethinus) and tree 7 (M. azedarach). Keywords: hotel open space, risky trees, Sonic Tomography, tree health monitoring, visual observation
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Boryczko, Krzysztof, et Barbara Tchórzewska-Cieślak. « Application of Fuzzy Fault Tree in Risk Analysis of Collective Water Supply Systems / ZASTOSOWANIE ROZMYTYCH DRZEW NIEZDATNOŚCI W ANALIZIE RYZYKA SYSTEMÓW ZBIOROWEGO ZAOPATRZENIA W WODĘ ». Journal of KONBiN 24, no 1 (1 décembre 2012) : 13–24. http://dx.doi.org/10.2478/jok-2013-0049.
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Abstract Application of the theory of using fuzzy fault trees is the first attempt to be used in collective water supply systems safety assessment in Poland. The paper presents a method of fault tree using fuzzy set theory. Fuzziness of basic logic gates used in the fault tree method is presented. The paper contains an application example of the method.
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Goodman, Katherine E., Justin Lessler, Anthony D. Harris, Aaron M. Milstone et Pranita D. Tamma. « A methodological comparison of risk scores versus decision trees for predicting drug-resistant infections : A case study using extended-spectrum beta-lactamase (ESBL) bacteremia ». Infection Control & ; Hospital Epidemiology 40, no 4 (4 mars 2019) : 400–407. http://dx.doi.org/10.1017/ice.2019.17.
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AbstractBackground:Timely identification of multidrug-resistant gram-negative infections remains an epidemiological challenge. Statistical models for predicting drug resistance can offer utility where rapid diagnostics are unavailable or resource-impractical. Logistic regression–derived risk scores are common in the healthcare epidemiology literature. Machine learning–derived decision trees are an alternative approach for developing decision support tools. Our group previously reported on a decision tree for predicting ESBL bloodstream infections. Our objective in the current study was to develop a risk score from the same ESBL dataset to compare these 2 methods and to offer general guiding principles for using each approach.Methods:Using a dataset of 1,288 patients with Escherichia coli or Klebsiella spp bacteremia, we generated a risk score to predict the likelihood that a bacteremic patient was infected with an ESBL-producer. We evaluated discrimination (original and cross-validated models) using receiver operating characteristic curves and C statistics. We compared risk score and decision tree performance, and we reviewed their practical and methodological attributes.Results:In total, 194 patients (15%) were infected with ESBL-producing bacteremia. The clinical risk score included 14 variables, compared to the 5 decision-tree variables. The positive and negative predictive values of the risk score and decision tree were similar (>90%), but the C statistic of the risk score (0.87) was 10% higher.Conclusions:A decision tree and risk score performed similarly for predicting ESBL infection. The decision tree was more user-friendly, with fewer variables for the end user, whereas the risk score offered higher discrimination and greater flexibility for adjusting sensitivity and specificity.
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Swari, Komang Kartika Indi, Dewa Ayu Intan Tirta Sari, Siti Fatimah Hanum Hanum et Ayyu Rahayu. « Evaluation on Fallen Trees of Hesperocyparis guadalupensis (S.Watson) Bartel and Pavetta sp. in Bali Botanic Garden Based on Visual Assessment and Acoustic Tomography ». Jurnal Ilmu Kehutanan 16, no 1 (31 mars 2022) : 108–14. http://dx.doi.org/10.22146/jik.v16i1.2173.
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The health of fallen tree collection especially which has not been assessed yet, has to be evaluated to understand its cause. This study aimed to see the health conditions of Cupressus guadalupensis and Pavetta sp. and the causes of fallen trees. The identification of tree health was done visually with a modified Tree Risk Assessment (TRA) form from the International Society of Arboriculture (ISA). Meanwhile, the internal examination used ArborSonic 3D Acoustic Tomograph. The tomogram results showed a hole in the tree trunk. The cause of the fallen trees was predicted due to structural damage with wind factors.
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Vitkus, Donatas, Jonathan Salter, Nikolaj Goranin et Dainius Čeponis. « Method for Attack Tree Data Transformation and Import Into IT Risk Analysis Expert Systems ». Applied Sciences 10, no 23 (26 novembre 2020) : 8423. http://dx.doi.org/10.3390/app10238423.
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Information technology (IT) security risk analysis preventatively helps organizations in identifying their vulnerable systems or internal controls. Some researchers propose expert systems (ES) as the solution for risk analysis automation since risk analysis by human experts is expensive and timely. By design, ES need a knowledge base, which must be up to date and of high quality. Manual creation of databases is also expensive and cannot ensure stable information renewal. These facts make the knowledge base automation process very important. This paper proposes a novel method of converting attack trees to a format usable by expert systems for utilizing the existing attack tree repositories in facilitating information and IT security risk analysis. The method performs attack tree translation into the Java Expert System Shell (JESS) format, by consistently applying ATTop, a software bridging tool that enables automated analysis of attack trees using a model-driven engineering approach, translating attack trees into the eXtensible Markup Language (XML) format, and using the newly developed ATES (attack trees to expert system) program, performing further XML conversion into JESS compatible format. The detailed method description, along with samples of attack tree conversion and results of conversion experiments on a significant number of attack trees, are presented and discussed. The results demonstrate the high method reliability rate and viability of attack trees as a source for the knowledge bases of expert systems used in the IT security risk analysis process.
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Hamid, Abdul, Ishak Bin Baba, Sulaiman Bin Haji Hasan, Agung Setyo Darmawan et Nushatisah. « Implementation of Risk Management in Manufacturing of Wellhead and Christmas Tree Equipment (Risk management framework) ». MATEC Web of Conferences 248 (2018) : 03013. http://dx.doi.org/10.1051/matecconf/201824803013.
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Wellheads and Christmas trees are the main equipment for oil production. They are manufactured in the plant and installed on the casing head to seal the annular space between casing and tubing. They are used to transport oil to pipeline in well field. The loss of wellhead and Christmas tree integrity can result in major accidents, presenting a severe risk to the environment. Therefor a purpose of this study is to investigate of an organization perception for risk management implementation in manufacturing wellhead and Christmas tree equipment. The responses were analysed using SPSS software by using Cronbach’s α, mean-value and standard deviation. Data was collected by posting a Google link form, or sent to the email of the companies listed in the Malaysia and Batam, Indonesia. This quantification of the risk management process and a risk identification tool onto the risk management process framework. The model can support and indicate the contribution of an industrial risk manager towards achieving project objectives, as well as making comprehensive decisions regarding analysis of risk management in manufacturing project and operation.
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SUSATYA, AGUS. « The potential risk of tree regeneration failure in species-rich Taba Penanjung lowland rainforest, Bengkulu, Indonesia ». Biodiversitas Journal of Biological Diversity 19, no 5 (21 septembre 2018) : 1891–901. http://dx.doi.org/10.13057/biodiv/d190542.
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Susatya A. 2018. The potential risk of tree regeneration failure in species-rich Taba Penanjung lowland rainforest, Bengkulu, Indonesia. Biodiversitas 19: 1891-1901. Tropical lowland rain forest is recognized by its high species richness with very few trees per species. It is also known for having tendency to outcrossing of its species with different floral sexualities, which requires the synchronization between flowering of its trees and the presence of pollinators. Such ecological attributes raise possible constraints for the forest trees to regenerate. The objective of the study was to assess the potential risk of failed regeneration for each tree species of the forest. Each of species with dbh of more than 5 cm in a one-ha plot was collected, identified, and its ecological criteria, including rarity, floral sexuality, seed size, and flowering phenology were determined. The potential risk of the failure of regeneration was calculated by summing all scores from Analytical Hierarchical Process of the criteria. The results indicated that the forest consisted of 118 species belonging to 69 genera and 37 families. Rare species accounted to 52.10% of the total species. Of the 118 species, the potential medium risk category contributed to 38.14%, and more than 33% were grouped into very high and high risk or were more prone to failed regeneration in the future. All rare dioecious species were categorized into very high and high risks. Only 21 species (17.79%) are listed in 2017’s IUCN red list. Among unevaluated species, 22 and 13 species were respectively included in very high and high potential risk categories. The results revealed more detailed potential risk of failed regeneration of tree species, and can serve as basic information to develop proper conservation management.
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Das, Adrian J., John J. Battles, Nathan L. Stephenson et Phillip J. van Mantgem. « The relationship between tree growth patterns and likelihood of mortality : a study of two tree species in the Sierra Nevada ». Canadian Journal of Forest Research 37, no 3 (mars 2007) : 580–97. http://dx.doi.org/10.1139/x06-262.
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We examined mortality of Abies concolor (Gord. & Glend.) Lindl. (white fir) and Pinus lambertiana Dougl. (sugar pine) by developing logistic models using three growth indices obtained from tree rings: average growth, growth trend, and count of abrupt growth declines. For P. lambertiana, models with average growth, growth trend, and count of abrupt declines improved overall prediction (78.6% dead trees correctly classified, 83.7% live trees correctly classified) compared with a model with average recent growth alone (69.6% dead trees correctly classified, 67.3% live trees correctly classified). For A. concolor, counts of abrupt declines and longer time intervals improved overall classification (trees with DBH ≥20 cm: 78.9% dead trees correctly classified and 76.7% live trees correctly classified vs. 64.9% dead trees correctly classified and 77.9% live trees correctly classified; trees with DBH <20 cm: 71.6% dead trees correctly classified and 71.0% live trees correctly classified vs. 67.2% dead trees correctly classified and 66.7% live trees correctly classified). In general, count of abrupt declines improved live-tree classification. External validation of A. concolor models showed that they functioned well at stands not used in model development, and the development of size-specific models demonstrated important differences in mortality risk between understory and canopy trees. Population-level mortality-risk models were developed for A. concolor and generated realistic mortality rates at two sites. Our results support the contention that a more comprehensive use of the growth record yields a more robust assessment of mortality risk.
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Ampuła, Dariusz. « Boosting Trees in Application to Hand Grenades Fuzes ». Journal of KONBiN 51, no 1 (1 mars 2021) : 43–55. http://dx.doi.org/10.2478/jok-2021-0004.
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Abstract The article in the introduction presents a brief description of the decision tree, and the purpose of the article was defined. Then, the process of building boosting trees was characterized, paying attention to the algorithm of their building. A method of building boosting trees for UZRGM fuzes is described. The assortment of fuzes in which this type of fuze is used is indicated, and the individual features of the fuze are presented, which are checked during laboratory diagnostic tests. The importance classes that were used to classify the revealed inconsistencies were also described. A boosting classification tree for UZRGM fuzes was designed and built. An exemplary graph of the built tree and its structure and also a fragment of specific values predicted in individual analyzed classes are shown. The matrix of incorrect classifications was determined, which determines the accuracy of the incorrect predictions. On selected examples of the analyzed classes, the designed model was assessed on the basis of the lift chart and gains chart.
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Lewis, Kevin, et Brian McCarthy. « Nontarget Tree Mortality after Tree-of-Heaven (Ailanthus altissima) Injection with Imazapyr ». Northern Journal of Applied Forestry 25, no 2 (1 juin 2008) : 66–72. http://dx.doi.org/10.1093/njaf/25.2.66.
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Abstract Tree-of-heaven (Ailanthus altissima Miller [Swingle]) can be managed easily with herbicide injection. However, the potential herbicide translocation to neighboring trees must be evaluated before widespread recommendations for herbicide injections. We assessed the nontargettranslocation of imazapyr (Arsenal), an herbicide commonly used to manage woody vegetation in forests, from injected tree-of-heaven to neighboring noninjected stems. Targeted imazapyr injections not only killed all injected tree-of-heaven, but also killed 17.5% of neighboring (within 3 m) noninjected tree-of-heaven and eight other tree species 62 weeks after treatment. Nontarget mortality from herbicide translocation decreased as the distance from injected tree-of-heaven increased (up to 3 m) and as stem diameter of noninjected plants increased. The plausible modes ofinter- and intraspecific herbicide translocation include root grafts, mutually shared mycorrhizal fungi, root exudation and absorption, and/or leaf senescence. Because tree-of-heaven is clonal, patch size and vegetation heterogeneity will be an important determinant of herbicide injectionprotocols. In forest environments with many small patches (i.e., high edge to interior ratio) or mixed species stands, nontarget hardwoods are at an increased risk of mortality. In isolated large patches (with lower edge to interior ratio) or dense monospecific clones, injection risk to nontarget species will be relatively low.
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Zulfikri, Fahmi, Dendy Tryanda, Allevia Syarif et Harry Patria. « Predicting Peer to Peer Lending Loan Risk Using Classification Approach ». International Journal of Advanced Science Computing and Engineering 3, no 2 (30 octobre 2021) : 94–100. http://dx.doi.org/10.30630/ijasce.3.2.57.
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Technological innovations have affected all sectors of life, especially, the financial sector with the emergence of financial technology. One of them is marked by the emergence of Peer-to-Peer Lending ("P2P Lending). Credit Risk Management is essential to P2P Lending as it directly affects business results, therefore it is important for P2P Lending to predict borrowers with the highest probability to become good or bad loans based on their profile or characteristics. In the experiments, five classification algorithms are used, which are Gradient Boosted Trees, Naïve Bayes, Random Forest, Decision Tree and Logistic Regression. The result is two modelling performed well that is Random Forest with accuracy 93.38% and Decision Tree with 92.35%.
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Abdullaev, A. S., et N. A. Abbasov. « Risk management and employment of advanced methods of risk estimation ». Azerbaijan Oil Industry, no 3 (15 mars 2020) : 52–57. http://dx.doi.org/10.37474/0365-8554/2020-3-52-57.
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The paper studies the methods applied in risk management and estimation. The brainstorming techniques, Delphi, the method of event tree analysis (ETA) and fault tree analysis (FTA), failure modes and effect analysis (FMEA), hazard and operability study are wide used. The pros and cons of risk management methods applied in world practice by leading companies were analysed. As a technique based on the study of logical connection between the hazardous events, “Tree event” method has its advantages. At the same time, the failure modes and effect analysis differs with simplicity and accessibility. It was defined that this technique is used as one of the most important tools in risk management almost in all spheres including petrochemistry and power economy. It is recommended to use HAZOP method in the analysis of project solutions and for risk estimation in later design stages. It is pointed out that in the context of improvement of risk management system, more qualitative risk estimation, the employment of advanced methods plays a significant role for goal achievement in the company and project decision-making as well.
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Hairiah, Kurniatun, Widianto Widianto, Didik Suprayogo et Meine Van Noordwijk. « Tree Roots Anchoring and Binding Soil : Reducing Landslide Risk in Indonesian Agroforestry ». Land 9, no 8 (1 août 2020) : 256. http://dx.doi.org/10.3390/land9080256.
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Tree root systems stabilize hillslopes and riverbanks, reducing landslide risk, but related data for the humid tropics are scarce. We tested fractal allometry hypotheses on differences in the vertical and horizontal distribution of roots of trees commonly found in agroforestry systems and on shear strength of soil in relation to root length density in the topsoil. Proximal roots of 685 trees (55 species; 4–20 cm stem diameter at breast height, dbh) were observed across six landscapes in Indonesia. The Index of Root Anchoring (IRA) and the Index of Root Binding (IRB) were calculated as ΣDv2/dbh2 and as ΣDh2/dbh2, respectively, where Dv and Dh are the diameters of vertical (angle > 45°) and horizontal (angle < 45°) proximal roots. High IRA values (>1.0) were observed in coffee and several common shade trees. Common fruit trees in coffee agroforestry had low medium values, indicating modest ‘soil anchoring’. Where root length density (Lrv) in the topsoil is less than 10 km m−3 shear strength largely depends on texture; for Lrv > 10 shear strength was >1.5 kg m−2 at the texture tested. In conclusion, a mix of tree species with deep roots and grasses with intense fine roots provides the highest hillslope and riverbank stability.