An evaluation of remotely sensed indices for quantifying burn severity in arid ecoregions

2019 ◽  
Vol 28 (12) ◽  
pp. 951
Author(s):  
Rob Klinger ◽  
Randy McKinley ◽  
Matt Brooks
Keyword(s):  
Remote Sensing ◽  
Mojave Desert ◽  
Remotely Sensed ◽  
High Elevation ◽  
Burn Severity ◽  
Elevation Gradients ◽  
Desert Regions ◽  
Woody Cover ◽  
The Difference ◽  
The Relationship

It is sometimes assumed the sparse and low statured vegetation in arid systems would limit the effectiveness of two remote-sensing derived indices of burn severity: the difference Normalised Burn Ratio (dNBR) and relativised difference Normalised Burn Ratio (RdNBR). We compared the relationship that dNBR, RdNBR and a ground-based index of burn severity (the Composite Burn Index, CBI) had with woody cover and woody density 1 year after burning in five fires that occurred in the Mojave Desert during 2005. Data were collected within 437 plots spanning geographic and elevation gradients representative of vegetation associations in low- (<1200m), mid- (1200 to 1700m) and high-elevation (>1700m) zones. Statistically, dNBR and RdNBR were both effective measures of severity in all three elevation zones; woody cover and density had steep exponential declines as the values of each remote-sensing index increased. We found though that dNBR was more ecologically interpretable than RdNBR and will likely be of most relevance in the Mojave Desert. It will be necessary though to test these, as well as other remote-sensing burn-severity indices, across more desert regions before inferences can be made of the generality of the patterns we observed.

scholarly journals A data science challenge for converting airborne remote sensing data into ecological information

2018 ◽  
Author(s):  
Sergio Marconi ◽  
Sarah J. Graves ◽  
Dihong Gong ◽  
Morteza Shahriari Nia ◽  
Marion Le Bras ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Quantitative Methods ◽  
Data Science ◽  
Remote Sensing Data ◽  
Remotely Sensed ◽  
Species Classification ◽  
Ecological Information ◽  
The Difference ◽  
Segmentation Task ◽  
Individual Trees

Ecology has reached the point where data science competitions, in which multiple groups solve the same problem using the same data by different methods, will be productive for advancing quantitative methods for tasks such as species identification from remote sensing images. We ran a competition to help improve three tasks that are central to converting images into information on individual trees: 1) crown segmentation, for identifying the location and size of individual trees; 2) alignment, to match ground truthed trees with remote sensing; and 3) species classification of individual trees. Six teams (composed of 16 individual participants) submitted predictions for one or more tasks. The crown segmentation task proved to be the most challenging, with the highest-performing algorithm yielding only 34% overlap between remotely sensed crowns and the ground truthed trees. However, most algorithms performed better on larger trees. For the alignment task, an algorithm based on minimizing the difference, in terms of both position and tree size, between ground truthed and remotely sensed crowns yielded a perfect alignment. In hindsight, this task was over simplified by only including targeted trees instead of all possible remotely sensed crowns. Several algorithms performed well for species classification, with the highest-performing algorithm correctly classifying 92% of individuals and performing well on both common and rare species. Comparisons of results across algorithms provided a number of insights for improving the overall accuracy in extracting ecological information from remote sensing. Our experience suggests that this kind of competition can benefit methods development in ecology and biology more broadly.

scholarly journals A data science challenge for converting airborne remote sensing data into ecological information

2018 ◽  
Author(s):  
Sergio Marconi ◽  
Sarah J. Graves ◽  
Dihong Gong ◽  
Morteza Shahriari Nia ◽  
Marion Le Bras ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Quantitative Methods ◽  
Data Science ◽  
Remote Sensing Data ◽  
Remotely Sensed ◽  
Species Classification ◽  
Ecological Information ◽  
The Difference ◽  
Segmentation Task ◽  
Individual Trees

Ecology has reached the point where data science competitions, in which multiple groups solve the same problem using the same data by different methods, will be productive for advancing quantitative methods for tasks such as species identification from remote sensing images. We ran a competition to help improve three tasks that are central to converting images into information on individual trees: 1) crown segmentation, for identifying the location and size of individual trees; 2) alignment, to match ground truthed trees with remote sensing; and 3) species classification of individual trees. Six teams (composed of 16 individual participants) submitted predictions for one or more tasks. The crown segmentation task proved to be the most challenging, with the highest-performing algorithm yielding only 34% overlap between remotely sensed crowns and the ground truthed trees. However, most algorithms performed better on larger trees. For the alignment task, an algorithm based on minimizing the difference, in terms of both position and tree size, between ground truthed and remotely sensed crowns yielded a perfect alignment. In hindsight, this task was over simplified by only including targeted trees instead of all possible remotely sensed crowns. Several algorithms performed well for species classification, with the highest-performing algorithm correctly classifying 92% of individuals and performing well on both common and rare species. Comparisons of results across algorithms provided a number of insights for improving the overall accuracy in extracting ecological information from remote sensing. Our experience suggests that this kind of competition can benefit methods development in ecology and biology more broadly.

scholarly journals Contrasting Geographic Patterns of Ignition Probability and Burn Severity in the Mojave Desert

2021 ◽  
Vol 9 ◽  
Author(s):  
Rob Klinger ◽  
Emma C. Underwood ◽  
Randy McKinley ◽  
Matthew L. Brooks
Keyword(s):  
Mojave Desert ◽  
Spatial Association ◽  
Fire Regimes ◽  
Fire Frequency ◽  
Burn Severity ◽  
Ignition Probability ◽  
Moderate Severity ◽  
Random Forest Models ◽  
The Difference ◽  
Normalized Burn Ratio

The extent and frequency of fire has increased in many arid systems over the last century, with a large proportion of area in some regions undergoing transitions to novel conditions. Portions of the Mojave Desert in southwestern North America have undergone such transitions, most often from woody to herbaceous-dominated systems. These transitions have often been attributed to the proliferation of invasive annual grasses that promote more frequent fire, but recent evidence indicates that transitions can also occur independent of fire frequency if burn severity is high. In addition, high probability of ignition (i.e., potentially high fire frequency) and high burn severity may not always be geographically related. Therefore, our goals were to: (1) map potential burn severity, fire frequency, and probability of ignition across the Mojave; and, (2) evaluate spatial association among predicted burn severity, fire frequency and probability of ignition. We first mapped perimeters of 250 wildfires > 405 ha that occurred from 1972 to 2010, then extracted data on fire frequency (number of times burned from 1972 to 2010), burn severity (the difference Normalized Burn Ratio), and 15 predictor variables representing physiography, climate, ignition, and vegetation. Maximum entropy was used to predict probability of ignition and Random Forest models were used to predict dNBR and fire frequency. Areas with high burn severity and high ignition probability had opposite spatial trends; areas with high burn severity were predicted to predominantly be in the northwest part of the region whereas areas with high ignition probability were predicted to be in the northeast. The models indicate the existence of a number of spatially structured but temporally dynamic fire regimes throughout the Mojave Desert. Two prevalent and ecologically significant regimes include one with frequent fires of low to moderate severity and another with infrequent fire of high severity. Areas with high fire frequency are currently limited in extent (<1% total area). However, cover of invasive grasses can remain high decades after a burn of high or moderate severity, so grass-fire cycles could develop in areas where there may be expectations of infrequent fire as well as those with relatively high fire frequency.

Comparison of In-the-Ear and Over-the-Ear Hearing Aid Fittings

1986 ◽  
Vol 51 (4) ◽  
pp. 362-369 ◽  
Author(s):  
Donna M. Risberg ◽  
Robyn M. Cox
Keyword(s):  
Hearing Aids ◽  
High Frequency ◽  
Comparative Evaluation ◽  
Speech Intelligibility ◽  
Hearing Aid ◽  
Hearing Aid Fitting ◽  
The Difference ◽  
Functional Gain ◽  
The Relationship

A custom in-the-ear (ITE) hearing aid fitting was compared to two over-the-ear (OTE) hearing aid fittings for each of 9 subjects with mild to moderately severe hearing losses. Speech intelligibility via the three instruments was compared using the Speech Intelligibility Rating (SIR) test. The relationship between functional gain and coupler gain was compared for the ITE and the higher rated OTE instruments. The difference in input received at the microphone locations of the two types of hearing aids was measured for 10 different subjects and compared to the functional gain data. It was concluded that (a) for persons with mild to moderately severe hearing losses, appropriately adjusted custom ITE fittings typically yield speech intelligibility that is equal to the better OTE fitting identified in a comparative evaluation; and (b) gain prescriptions for ITE hearing aids should be adjusted to account for the high-frequency emphasis associated with in-the-concha microphone placement.

Relationship between total plasma homocysteine and the risk of aneurysms – a meta-analysis

VASA ◽  
2020 ◽  
pp. 1-6
Author(s):  
Hanji Zhang ◽  
Dexin Yin ◽  
Yue Zhao ◽  
Yezhou Li ◽  
Dejiang Yao ◽  
...  
Keyword(s):  
Large Scale ◽  
Meta Analysis ◽  
Single Species ◽  
Total Plasma ◽  
Control Groups ◽  
Randomized Controlled ◽  
Randomized Controlled Studies ◽  
The Difference ◽  
The Relationship ◽  
Healthy Participants

Summary: Our meta-analysis focused on the relationship between homocysteine (Hcy) level and the incidence of aneurysms and looked at the relationship between smoking, hypertension and aneurysms. A systematic literature search of Pubmed, Web of Science, and Embase databases (up to March 31, 2020) resulted in the identification of 19 studies, including 2,629 aneurysm patients and 6,497 healthy participants. Combined analysis of the included studies showed that number of smoking, hypertension and hyperhomocysteinemia (HHcy) in aneurysm patients was higher than that in the control groups, and the total plasma Hcy level in aneurysm patients was also higher. These findings suggest that smoking, hypertension and HHcy may be risk factors for the development and progression of aneurysms. Although the heterogeneity of meta-analysis was significant, it was found that the heterogeneity might come from the difference between race and disease species through subgroup analysis. Large-scale randomized controlled studies of single species and single disease species are needed in the future to supplement the accuracy of the results.

Klein with Lacan: A Study on the Reception of Lacanian Ideas in Uruguay and Its Effects on Clinical Practices (1955–82)

2020 ◽  
Vol 22 (3) ◽  
pp. 341-361
Author(s):  
Gonzalo Grau-Pérez ◽  
J. Guillermo Milán
Keyword(s):  
Clinical Practice ◽  
Clinical Material ◽  
Clinical Practices ◽  
Before And After ◽  
The Difference ◽  
The 1960S ◽  
The Relationship ◽  
Discursive Approach ◽  
The Way ◽  
Clinical Cases

In Uruguay, Lacanian ideas arrived in the 1960s, into a context of Kleinian hegemony. Adopting a discursive approach, this study researched the initial reception of these ideas and its effects on clinical practices. We gathered a corpus of discursive data from clinical cases and theoretical-doctrinal articles (from the 1960s, 1970s and 1980s). In order to examine the effects of Lacanian ideas, we analysed the difference in the way of interpreting the clinical material before and after Lacan's reception. The results of this research illuminate some epistemological problems of psychoanalysis, especially the relationship between theory and clinical practice.

The End of the Word as We Know It

2012 ◽  
Vol 6 (1-3) ◽  
pp. 165-184
Author(s):  
Timothy Beal
Keyword(s):  
Cultural Meanings ◽  
Cultural Icon ◽  
The Bible ◽  
Material Objectivity ◽  
The Difference ◽  
The Relationship

This essay attends to a distinction that requires closer examination and theorization in our discourse on iconic books and other scriptures: the difference between iconic object and cultural icon. How do we conceive of relations between the particular, ritualized iconicities of particular scriptures in particular religious contexts and the cultural iconicities of scriptures in general, such as “the Bible” or “the Quran,” whose visual and material objectivity is highly ambiguous? How if at all are the iconic cultural meanings of the ideas of such books related to the particular iconic textual objects more or less instantiate them? These questions are explored through particular focus on the relationship between the particular iconicities of particular print Bibles, as iconic objects, and the general iconicity of the cultural icon of the Bible.

Learning Language Levels in Students Accurate with a History Academic Achievement History

2017 ◽  
Vol 1 (2) ◽  
pp. 137
Author(s):  
Noorlela Binti Noordin ◽  
Abdul Razaq Ahmad ◽  
Anuar Ahmad
Keyword(s):  
Academic Achievement ◽  
Statistical Inference ◽  
Quantitative Data ◽  
Quantitative Methods ◽  
Descriptive Statistics ◽  
Language Test ◽  
The Subject ◽  
The Difference ◽  
Learning Language ◽  
The Relationship

This study was aimed to evaluate the Malay proficiency among students in Form Two especially non-Malay students and its relationship to academic achievement History. To achieve the purpose of the study there are two objectives, the first is to look at the difference between mean of Malay Language test influences min of academic achievement of History subject among non-Malay students in Form Two and the second is the relationship between the level of Malay proficiency and their academic achievement for History. This study used quantitative methods, which involved 100 people of Form Two non-Malay students in one of the schools in Klang, Selangor. This study used quantitative data were analyzed using descriptive statistics and statistical inference with IBM SPSS Statistics v22 software. This study found that there was a relationship between the proficiency of Malay language among non-Malay students with achievements in the subject of History. The implications of this study are discussed in this article.

THE ROLE OF REMOTE SENSING DATA FOR COASTAL ZONE MONITIORING AND MANAGEMENT (CASE STUDY FOR THE EAST PART OF GULF OF FINLAND)

2017 ◽  
Author(s):  
Nikifor Ostanin ◽  
Nikifor Ostanin
Keyword(s):  
Remote Sensing ◽  
Coastal Zone ◽  
Environmental Changes ◽  
Rapid Development ◽  
Water Environment ◽  
Remote Sensing Data ◽  
Remotely Sensed ◽  
Gulf Of Finland ◽  
Coastal Protection ◽  
Remotely Sensed Data

Coastal zone of the Eastern Gulf of Finland is subjected to essential natural and anthropogenic impact. The processes of abrasion and accumulation are predominant. While some coastal protection structures are old and ruined the problem of monitoring and coastal management is actual. Remotely sensed data is important component of geospatial information for coastal environment research. Rapid development of modern satellite remote sensing techniques and data processing algorithms made this data essential for monitoring and management. Multispectral imagers of modern high resolution satellites make it possible to produce advanced image processing, such as relative water depths estimation, sea-bottom classification and detection of changes in shallow water environment. In the framework of the project of development of new coast protection plan for the Kurortny District of St.-Petersburg a series of archival and modern satellite images were collected and analyzed. As a result several schemes of underwater parts of coastal zone and schemes of relative bathymetry for the key areas were produced. The comparative analysis of multi-temporal images allow us to reveal trends of environmental changes in the study areas. This information, compared with field observations, shows that remotely sensed data is useful and efficient for geospatial planning and development of new coast protection scheme.

Investigating the Personality Variable (LOC) & Impression Management Relationship: Exploring the Role of Demographic Variables & Sectoral Difference of Managers

2016 ◽  
Vol 7 (1) ◽  
Author(s):  
Poornima Madan ◽  
Shalini Srivastava
Keyword(s):  
Locus Of Control ◽  
Impression Management ◽  
Demographic Variables ◽  
Personality Variable ◽  
Public Sector Organizations ◽  
Private And Public ◽  
The Difference ◽  
The Relationship ◽  
Test Correlation

The purpose of the study is to investigate the relationship between locus of control and impression management. The study also examines the variation in locus of control dimensions namely, internality, externality (others) and externality (chance). It further investigates the difference on perception of demographic variables (gender and marital status) and sectoral difference on impression management. The study was administered on 125 Managers who were representatives of different private and public sector organizations in Delhi/NCR. Variables in the study were assessed using validated instruments. Descriptive Statistics, t-test, Correlation and Regression were used for data analysis. Organizations will be better prepared to dig into the arena of one of the personality variable, i.e. locus of control and its relationship with impression management. The current research is imperative in providing insights into role of personality variable (locus of control) and impression management, which will be one of the pioneer researches available till date. Moreover, the research will highlight the significance of locus of control dimensions and impression management.

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