scholarly journals Ecological associations among epidermal microstructure and scale characteristics of Australian geckos (Squamata: Carphodactylidae and Diplodactylidae)

2019 ◽  
Vol 234 (6) ◽  
pp. 853-874 ◽  
Author(s):  
Jendrian Riedel ◽  
Matthew J. Vucko ◽  
Simone P. Blomberg ◽  
Simon K. A. Robson ◽  
Lin Schwarzkopf
Keyword(s):  
Scale Characteristics ◽  
Ecological Associations

scholarly journals A Review of Current Research in Subscale Flight Testing and Analysis of Its Main Practical Challenges

Aerospace ◽  
2021 ◽  
Vol 8 (3) ◽  
pp. 74
Author(s):  
Alejandro Sobron ◽  
David Lundström ◽  
Petter Krus
Keyword(s):  
Literature Review ◽  
Research And Development ◽  
Rapid Prototyping ◽  
Experimental Method ◽  
Low Cost ◽  
Full Scale ◽  
Interesting Application ◽  
Flight Testing ◽  
Scale Characteristics ◽  
Vehicle Technologies

Testing of untethered subscale models, often referred to as subscale flight testing, has traditionally had a relatively minor, yet relevant use in aeronautical research and development. As recent advances in electronics, rapid prototyping and unmanned-vehicle technologies expand its capabilities and lower its cost, this experimental method is seeing growing interest across academia and the industry. However, subscale models cannot meet all similarity conditions required for simulating full-scale flight. This leads to a variety of approaches to scaling and to other alternative applications. Through a literature review and analysis of different scaling strategies, this study presents an overall picture of how subscale flight testing has been used in recent years and synthesises its main issues and practical limitations. Results show that, while the estimation of full-scale characteristics is still an interesting application within certain flight conditions, subscale models are progressively taking a broader role as low-cost technology-testing platforms with relaxed similarity constraints. Different approaches to tackle the identified practical challenges, implemented both by the authors and by other organisations, are discussed and evaluated through flight experiments.

scholarly journals A new multi-scale backbone network for object detection based on asymmetric convolutions

2021 ◽  
Vol 104 (2) ◽  
pp. 003685042110113
Author(s):  
Xianghua Ma ◽  
Zhenkun Yang
Keyword(s):  
Object Detection ◽  
Image Features ◽  
Detection Accuracy ◽  
Mobile Platforms ◽  
Multi Scale ◽  
Backbone Network ◽  
Aspect Ratios ◽  
Pascal Voc ◽  
Scale Characteristics ◽  
Detection Speed

Real-time object detection on mobile platforms is a crucial but challenging computer vision task. However, it is widely recognized that although the lightweight object detectors have a high detection speed, the detection accuracy is relatively low. In order to improve detecting accuracy, it is beneficial to extract complete multi-scale image features in visual cognitive tasks. Asymmetric convolutions have a useful quality, that is, they have different aspect ratios, which can be used to exact image features of objects, especially objects with multi-scale characteristics. In this paper, we exploit three different asymmetric convolutions in parallel and propose a new multi-scale asymmetric convolution unit, namely MAC block to enhance multi-scale representation ability of CNNs. In addition, MAC block can adaptively merge the features with different scales by allocating learnable weighted parameters to three different asymmetric convolution branches. The proposed MAC blocks can be inserted into the state-of-the-art backbone such as ResNet-50 to form a new multi-scale backbone network of object detectors. To evaluate the performance of MAC block, we conduct experiments on CIFAR-100, PASCAL VOC 2007, PASCAL VOC 2012 and MS COCO 2014 datasets. Experimental results show that the detection precision can be greatly improved while a fast detection speed is guaranteed as well.

Multi-scale characteristics of remote sensing lineaments

2019 ◽  
Vol 13 (2) ◽  
pp. 287-297
Author(s):  
Junlong Xu ◽  
Xingping Wen ◽  
Haonan Zhang ◽  
Dayou Luo ◽  
Lianglong Xu ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Multi Scale ◽  
Scale Characteristics

Patterns of Evolution of the Ediacaran Soft-Bodied Biota

2014 ◽  
Vol 88 (2) ◽  
pp. 269-283 ◽  
Author(s):  
Dmitriy Grazhdankin
Keyword(s):  
High Energy ◽  
Ecosystem Engineering ◽  
Low Energy ◽  
Geological Time ◽  
Time Intervals ◽  
Inner Shelf ◽  
Sedimentary Environments ◽  
Burrowing Activity ◽  
Ecological Associations ◽  
Channel Systems

When each of the Avalon-, Ediacara-, and Nama-type fossil assemblages are tracked through geological time, there appear to be changes in species composition and diversity, almost synchronized between different sedimentary environments, allowing a subdivision of the late Ediacaran into the Redkinian, Belomorian and Kotlinian geological time intervals. The Redkinian (580–559 Ma) is characterized by first appearance of both eumetazoan traces and macroscopic organisms (frondomorphs and vendobionts) in a form of Avalon-type communities in the inner shelf environment, whereas coeval Ediacara-type communities remained depauperate. The Belomorian (559–550 Ma) is marked by the advent of eumetazoan burrowing activity in the inner shelf, diversification of frondomorphs, migration of vendobionts from the inner shelf into higher energy environments, and appearance of tribrachiomorphs and bilateralomorphs. Ediacaran organisms formed distinctive ecological associations that coexisted in the low-energy inner shelf (Avalon-type communities), in the wave- and current-agitated shoreface (Ediacara-type communities), and in the high-energy distributary systems (Nama-type communities). The Kotlinian (550–540 Ma) witnessed an expansion of the burrowing activity into wave- and current-agitated shoreface, disappearance of vendobionts, tribrachiomorphs and bilateralomorphs in wave- and current-agitated shoreface, together with a drop in frondomorph diversity. High-energy distributary channel systems of prodeltas served as refugia for Nama-type communities that survived until the end of the Ediacaran and disappeared when the burrowing activity reached high-energy environments. This pattern is interpreted as an expression of ecosystem engineering by eumetazoans, with the Ediacaran organisms being progressively outcompeted by bilaterians.

Equilibrium and Kinetic Properties of Minerals

1998 ◽  
Vol 62 (5) ◽  
pp. 581-583
Author(s):  
Simon A. T. Redfern
Keyword(s):  
Solid State ◽  
Statistical Mechanics ◽  
Structural Features ◽  
Atomic Scale ◽  
Kinetic Properties ◽  
Computational Power ◽  
Equilibrium Thermodynamics ◽  
Bulk Properties ◽  
Scale Characteristics ◽  
Number Of Publications

How can the equilibrium and non-equilibrium thermodynamics of minerals be understood from their atomic-scale structural features? How can they be predicted, simply from models for the forces between atoms? Advances in analytical theory, statistical mechanics, experimental solid-state science, computational power, and the sophistication of a mineralogical approach that brings all of these together, means that these questions, once imponderable, are now realistically tractable. These questions have been exercising the minds of mineralogists over the last decade or so, and have motivated many developments in the science. Acting as way-markers along the path, there are a number of publications which have followed from meetings where these questions have been addressed. It is now twelve years since the publication of Microscopic to Macroscopic, an edition of Reviews in Mineralogy (Kieffer and Navrotsky, 1985) that sought to identify the fundamental controls on the bulk properties of minerals in terms of their atomic-scale characteristics.

Recognition of larvae of the Tetrabothriidae (Eucestoda): implications for the origin of tapeworms in marine homeotherms

1987 ◽  
Vol 65 (4) ◽  
pp. 997-1000 ◽  
Author(s):  
Eric P. Hoberg
Keyword(s):  
Life History ◽  
Phylogenetic Relationships ◽  
Host Switching ◽  
Larval Morphology ◽  
Dominant Group ◽  
Marine Birds ◽  
Marine Communities ◽  
Definitive Evidence ◽  
Life History Patterns ◽  
Ecological Associations

The Tetrabothriidae represent the dominant group of cestodes, previously known only as adult parasites, in marine birds and mammals. Recognition of their unique plerocercoid larvae provides the first definitive evidence for life history patterns and phylogenetic relationships with other cestodes. Affinities of the Tetrabothriidae and Tetraphyllidea, cestodes of elasmobranchs, are indicated by larval morphology and ontogeny. However, patterns of sequential heterochrony in the ontogeny of the adult scolex of Tetrabothrius sp. appear to be unique among the Eucestoda. Tetrabothriids constitute a fauna that originated by host switching from elasmobranchs to homeotherms, via ecological associations, following invasion of marine communities by birds and mammals in the Tertiary.

Technical Adequacy of the Positive Experiences at School Scale With Adolescents

2016 ◽  
Vol 35 (3) ◽  
pp. 323-335 ◽  
Author(s):  
Tyler L. Renshaw
Keyword(s):  
Grade Level ◽  
School Connectedness ◽  
Future Research ◽  
Technical Adequacy ◽  
Confirmatory Factor Analyses ◽  
Black African ◽  
Means Testing ◽  
Confirmatory Factor ◽  
Scale Characteristics ◽  
Current Sample

The present study reports on an investigation of the generalizability of the technical adequacy of the Positive Experience at School Scale (PEASS) with a sample of students ( N = 1,002) who differed substantially in age/grade level (i.e., adolescents in middle school as opposed to children in elementary school) and ethnic identity (i.e., majority Black/African American as opposed to majority Latino/a) in comparison with the measure’s primary development sample. Findings from confirmatory factor analyses indicated the original latent structure of the PEASS was tenable in the current sample and that the measure was invariant across gender and grade level, with some small demographic differences identified via latent means testing. Additional psychometric findings regarding the technical adequacy of the PEASS with this sample, including its observed scale characteristics and simulated classification utility with criterion measures of academic self-efficacy and school connectedness, are also presented. Implications for future research and practice are discussed.

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