U.S. flag

An official website of the United States government

PubAg

Main content area

You searched for: Subject "trees" Remove constraint Subject: "trees"
Start Over

Search

74,606  Search Results

« Previous | 1 - 20 of 74,606 |
Number of results to display per page

Search Results

1. Patent Nash equilibria in symmetric strictly competitive games

Author:
Bahel, Eric
Source:
Economics letters 2021 v.199 pp. 109733
ISSN:
0165-1765
Subject:
trees,   etc   ; economics; games;     Show all 3 Subjects
Abstract:
... This work refines the notion of Nash equilibrium in the case of symmetric strictly competitive games. We define a (complete and typically intransitive) binary relation allowing to identify the so-called latent actions, for which there exists a maximal tree whose nodes are all preferred to the considered action. We prove the existence of patent Nash equilibria (obtained after iterated elimination o ...
DOI:
10.1016/j.econlet.2021.109733

2. Heuristics for unrooted, unranked, and ranked anomaly zones under birth-death models

Author:
Kim, Anastasiia; Degnan, James H.
Source:
Molecular phylogenetics and evolution 2021 pp. 107162
ISSN:
1055-7903
Subject:
trees,   etc   ; genes; phylogeny; probability; topology;     Show all 5 Subjects
Abstract:
... Species trees that can generate a nonmatching gene tree topology that is more probable than the topology matching the species tree are said to be in an anomaly zone. We introduce some heuristic approaches to infer whether species trees are in anomaly zones when it is difficult or impossible to compute the entire distribution of gene tree topologies. Here, probabilities of unrooted, unranked, and r ...
DOI:
10.1016/j.ympev.2021.107162

3. Disentangling the contributions of urban and production sources in short- and medium-chain chlorinated paraffin concentrations in a complex source region

Author:
Niu, Shan; Chen, Ruiwen; Hageman, Kimberly J.; Zou, Yun; Dong, Liang; Zheng, Ran; Wang, Xiaohui; Hai, Reti
Source:
Journal of hazardous materials 2021 v.405 pp. 124117
ISSN:
0304-3894
Subject:
trees,   etc   ; air; bark; equations; wind;     Show all 5 Subjects
Abstract:
... Short-chain chlorinated paraffins (SCCPs) and medium-chain chlorinated paraffins (MCCPs) were measured in tree bark samples. These samples were collected around a chemical industrial park containing several chlorinated paraffin (CP) production plants, in a nearby city (Zhengzhou), and along a transect between the industrial park and city. Theoretical air concentrations were back-calculated from co ...
DOI:
10.1016/j.jhazmat.2020.124117

4. Steps-based tree crown delineation by analyzing local minima for counting the trees in very high resolution satellite imagery

Author:
Chakraborty, Debasish; Kumar, Pranshu
Source:
Geocarto international 2021 v.36 no.1 pp. 110-120
ISSN:
1752-0762
Subject:
trees,   etc   ; remote sensing; tree crown;     Show all 3 Subjects
Abstract:
... In this study primarily, high-resolution (HR) satellite image is segmented into tree and non-tree regions. Thereafter plots the local minima in the segmented image. Point surrounded by the higher intensity values is called as local minima. The local minimum is the starting point for marking the tree crown boundary. The adjacent darker points along the local minima are plotted in a specific directi ...
DOI:
10.1080/10106049.2019.1611947

5. Additive trees for the categorization of a large number of objects, with bootstrapping strategy for stability assessment. Application to the free sorting of wine odor terms

Author:
Koenig, L.; Cariou, V.; Symoneaux, R.; Coulon-Leroy, C.; Vigneau, E.
Source:
Food quality and preference 2021 v.89 pp. 104137
ISSN:
0950-3293
Subject:
trees,   etc   ; algorithms; cohesion; food quality; odors; wines;     Show all 6 Subjects
Abstract:
... In the field of clustering techniques, little attention has been paid to the recovery of a set of clusters from the structure of an additive tree. To bridge this gap, this work presents an original partitioning technique which aims to reveal clusters from an additive tree that represents a large set of objects. Specifically, an algorithm that splits a tree into successive subtrees was developed, b ...
DOI:
10.1016/j.foodqual.2020.104137

6. Analysis of Fluid–Structure Coupling Vibration Mechanism for Subsea Tree Pipeline Combined with Fluent and Ansys Workbench

Author:
Wu, Gongxing; Zhao, Xiaolong; Shi, Danda; Wu, Xiaodong
Source:
Water 2021 v.13 no.7
ISSN:
2073-4441
Subject:
trees,   etc   ; computer software; models; oils; vibration; water;     Show all 6 Subjects
Abstract:
... In the process of oil exploitation, subseatrees sometimes vibrate. In this paper, fluid–structure coupling software was used to study the causes of subsea tree vibration. First, the complex subsea tree model was simplified, and ageometric grid model was established for software calculation. Then, under the given two working conditions, the software Fluent was used to analyze the pressure and veloc ...
DOI:
10.3390/w13070955

7. Genetics and Improvement of Forest Trees

Author:
Ide, Yuji
Source:
Forests 2021 v.12 no.2
ISSN:
1999-4907
Subject:
forest trees,   etc   ; forests; genetics; plant improvement;     Show all 4 Subjects
Abstract:
... Forest tree improvement has mainly been implemented to enhance the productivity of artificial forests [...] ...
DOI:
10.3390/f12020182

8. Hierarchical copulas with Archimedean blocks and asymmetric between-block pairs

Author:
Chaoubi, Ihsan; Cossette, Hélène; Marceau, Etienne; Robert, Christian Y.
Source:
Computational statistics & data analysis 2021 v.154 pp. 107071
ISSN:
0167-9473
Subject:
trees,   etc   ; data analysis; data collection; estimation; mixing;     Show all 5 Subjects
Abstract:
... A new class of hierarchical copulas is introduced based on joint survival functions of multivariate exponential mixture distributions. The key element of this construction is the mixing random vector defined by convolutions associated to a Lévy subordinator, and leading to hierarchical copulas with Archimedean within-block copulas and asymmetric between-block pair-copulas. For the specific case of ...
DOI:
10.1016/j.csda.2020.107071

9. Towards a subtropical forest spectral library: spectra consistency and spectral separability

Author:
Bao, Shanning; Cao, Chunxiang; Chen, Wei; Yang, Tianyu; Wu, Chunying
Source:
Geocarto international 2021 v.36 no.2 pp. 226-240
ISSN:
1752-0762
Subject:
trees,   etc   ; analysis of variance; leaves; tropical forests;     Show all 4 Subjects
Abstract:
... To meet the demand of standard spectral information for the subtropical forest, a three-level spectral library including leaf spectra of 67 typical subtropical tree species was built using two spectrometers. Towards the spectra measured by different spectrometers, the spectra consistency was tested using one-way Analysis of Variance (ANOVA) and Jeffries-Matusita distance (J-M distance). The optima ...
DOI:
10.1080/10106049.2019.1608589

10. Quantifying the vertical diversification development stage of old-growth Douglas-fir to derive stage-specific targets for restoration silviculture

Author:
Zenner, Eric K.; Peck, JeriLynn E.
Source:
Canadian journal of forest research 2021 v.51 no.3 pp. 484-492
ISSN:
1208-6037
Subject:
trees,   etc   ; Oregon; Pseudotsuga menziesii; research; silviculture;     Show all 5 Subjects
Abstract:
... Structural variability in natural Douglas-fir (Pseudotsuga menziesii (Mirbel) Franco) forests hinders restoration targets for the full old-growth developmental sequence. To guide stage-specific restoration, we present a new approach toward developing a simple index of the vertical diversification (VD) stage. VD-associated sub-stand structures were objectively identified by quantifying the size str ...
DOI:
10.1139/cjfr-2020-0244

11. Rebuilding Tree Cover in Deforested Cocoa Landscapes in Côte d’Ivoire: Factors Affecting the Choice of Species Planted

Author:
Atangana, Alain R.; Gnangoh, Juvenal Zahoui; Yao, Allegra Kouassi; Kouakou, Thomas d’Aquin; Mian Ndri Nda, Anatole; Kouamé, Christophe
Source:
Forests 2021 v.12 no.2
ISSN:
1999-4907
Subject:
forest trees; fruit trees,   etc   ; agricultural policy; agroforestry; deforestation; farmers; farms; forests; income; Cote d'Ivoire;     Show all 10 Subjects
Abstract:
... Intensive cocoa production in Côte d’Ivoire, the world’s leading cocoa producer, has grown at the expense of forest cover. To reverse this trend, the country has adopted a “zero deforestation” agricultural policy and committed to rehabilitating its forest cover through the planting of high-value tree species in cocoa landscapes using a participatory approach. However, little is known regarding the ...
DOI:
10.3390/f12020198

12. Dendrochronologia’s tutoring recipes: How to take samples for small basic dendroecological studies

Author:
Cherubini, Paolo; Gargano, Alice; Grob, Marc; Nievergelt, Daniel; Passardi, Silvia
Source:
Dendrochronologia 2020 v.64 pp. 125774
ISSN:
1125-7865
Subject:
trees,   etc   ; dendroecology; recipes; sampling;     Show all 4 Subjects
Abstract:
... This technical note and its corresponding video aim to show how to sample trees for small basic dendroecological studies. Video ...
DOI:
10.1016/j.dendro.2020.125774

13. Phenotypic characters of static homology increase phylogenetic stability under direct optimization of otherwise dynamic homology characters

Author:
Lehtonen, Samuli
Source:
Cladistics 2020 v.36 no.6 pp. 617-626
ISSN:
0748-3007
Subject:
trees,   etc   ; phenotype; phylogeny;     Show all 3 Subjects
Abstract:
... Direct optimization of unaligned sequence characters provides a natural framework to explore the sensitivity of phylogenetic hypotheses to variation in analytical parameters. Phenotypic data, when combined into such analyses, are typically analyzed with static homology correspondences unlike the dynamic homology sequence data. Static homology characters may be expected to constrain the direct opti ...
DOI:
10.1111/cla.12438

14. ROC‐guided survival trees and ensembles

Author:
Sun, Yifei; Chiou, Sy Han; Wang, Mei‐Cheng
Source:
Biometrics 2020 v.76 no.4 pp. 1177-1189
ISSN:
0006-341X
Subject:
trees,   etc   ; algorithms; prediction;     Show all 3 Subjects
Abstract:
... Tree‐based methods are popular nonparametric tools in studying time‐to‐event outcomes. In this article, we introduce a novel framework for survival trees and ensembles, where the trees partition the dynamic survivor population and can handle time‐dependent covariates. Using the idea of randomized tests, we develop generalized time‐dependent receiver operating characteristic (ROC) curves for evalua ...
DOI:
10.1111/biom.13213

15. The effects of ascent technique and the presence of leaves on loading of a tie-in point during climber ascents

Author:
Brian, Kane; Emma, Brigham; Arwade, Sanjay R.
Source:
Urban forestry & urban greening 2020 v.54 pp. 126762
ISSN:
1618-8667
Subject:
trees,   etc   ; branches; leaves;     Show all 3 Subjects
Abstract:
... The use of throwlines has made it easier for climbers on the ground to set a tie-in point (TIP) near the top of the tree. But doing so may increase the likelihood of TIP failure because smaller branches have less load-bearing capacity and close inspection of the TIP from the ground is difficult. We measured rope tension during climber ascents on stationary rope systems on ten TIPs from two species ...
DOI:
10.1016/j.ufug.2020.126762

16. Lightning‐caused disturbance in the Peruvian Amazon

Author:
Gora, Evan M.; Yanoviak, Stephen P.
Source:
Biotropica 2020 v.52 no.5 pp. 813-817
ISSN:
0006-3606
Subject:
trees,   etc   ; diameter; lightning; Amazonia;     Show all 4 Subjects
Abstract:
... We surveyed seven lightning strike sites in the northern Peruvian Amazon. An average of 17.3 trees were damaged per strike; large trees (> 60 cm diameter) were disproportionately affected. The results contribute to a growing body of evidence that lightning is an important agent of disturbance pantropically. Abstract in Spanish is available with online material. ...
DOI:
10.1111/btp.12826

17. Tree‐gouging by marmosets (Primates: Callitrichidae) enhances tree turnover

Author:
Souza‐Alves, João Pedro; Barbosa, Guilherme V.; Hilário, Renato Richard
Source:
Biotropica 2020 v.52 no.5 pp. 808-812
ISSN:
0006-3606
Subject:
trees,   etc   ; Callithrix jacchus; forests;     Show all 3 Subjects
Abstract:
... We tested whether gouging by Callithrix jacchus affects tree survival. The proportion of dead gouged trees was higher than the proportion of dead non‐gouged trees, with larger effects on smaller trees. The number of holes did not affect tree survival. Tree‐gouging by marmosets may enhance forest turnover. Abstract in Portuguese is available with online material. ...
DOI:
10.1111/btp.12825

18. Should Networks Supplant Tree Building?

Author:
DeSalle, Rob; Riley, Margaret
Source:
Microorganisms 2020 v.8 no.8
ISSN:
2076-2607
Subject:
trees,   etc   ; Archaea; death; phylogeny;     Show all 4 Subjects
Abstract:
... Recent studies suggested that network methods should supplant tree building as the basis of genealogical analysis. This proposition is based upon two arguments. First is the observation that bacterial and archaeal lineages experience processes oppositional to bifurcation and hence the representation of the evolutionary process in a tree like structure is illogical. Second is the argument tree buil ...
DOI:
10.3390/microorganisms8081179

19. Estimation of rare and clustered population mean using stratified adaptive cluster sampling

Author:
Qureshi, Muhammad Nouman; Kadilar, Cem; Hanif, Muhammad
Source:
Environmental and ecological statistics 2020 v.27 no.1 pp. 151-170
ISSN:
1352-8505
Subject:
trees,   etc   ; Sequoia sempervirens; California;     Show all 3 Subjects
Abstract:
... For many clustered populations, the prior information on an initial stratification exists but the exact pattern of the population concentration may not be predicted. Under this situation, the stratified adaptive cluster sampling (SACS) may provide more efficient estimates than the other conventional sampling designs for the estimation of rare and clustered population parameters. For practical inte ...
DOI:
10.1007/s10651-019-00438-z

20. Loads borne by a tie-in point (TIP) during arboricultural climbing operations

Author:
Kane, Brian
Source:
Urban forestry & urban greening 2020 v.49 pp. 126625
ISSN:
1618-8667
Subject:
trees,   etc   ; arboriculture; leaves;     Show all 3 Subjects
Abstract:
... Failure of a tie-in point (TIP) in tree climbing can have severe consequences, yet few studies have quantified the loads borne by and load-bearing capacity of TIPs. In two separate experiments, loads borne by the TIP during (i) abrupt stops while a climber descended and (ii) simulated climber falls were quantified for a variety of TIPs, rope types, and rope lengths (distance between the TIP and th ...
DOI:
10.1016/j.ufug.2020.126625