scholarly journals Symmetry in Self-Similarity in Space and Time—Short Time Transients and Power-Law Spatial Asymptotes

Symmetry ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 1489
Author(s):  
Ken Sekimoto ◽  
Takahiko Fujita
Keyword(s):  
Power Law ◽  
Late Stage ◽  
Scaling Function ◽  
Early Stage ◽  
The Self ◽  
Scaling Functions ◽  
Self Similarity ◽  
Simple Diffusion ◽  
Early Stages ◽  
Space And Time

The self-similarity in space and time (hereafter self-similarity), either deterministic or statistical, is characterized by similarity exponents and a function of scaled variable, called the scaling function. In the present paper, we address mainly the self-similarity in the limit of early stage, as opposed to the latter one, and also consider the scaling functions that decay or grow algebraically, as opposed to the rapidly decaying functions such as Gaussian or error function. In particular, in the case of simple diffusion, our symmetry analysis shows a mathematical mechanism by which the rapidly decaying scaling functions are generated by other polynomial scaling functions. While the former is adapted to the self-similarity in the late-stage processes, the latter is adapted to the early stages. This paper sheds some light on the internal structure of the family of self-similarities generated by a simple diffusion equation. Then, we present an example of self-similarity for the late stage whose scaling function has power-law tail, and also several cases of self-similarity for the early stages. These examples show the utility of self-similarity to a wider range of phenomena other than the late stage behaviors with rapidly decaying scaling functions.

scholarly journals Transition from Self-Organized Criticality into Self-Organization during Sliding Si3N4 Balls against Nanocrystalline Diamond Films

Entropy ◽  
2019 ◽  
Vol 21 (11) ◽  
pp. 1055
Author(s):  
Bogatov ◽  
Podgursky ◽  
Vagiström ◽  
Yashin ◽  
Shaikh ◽  
...  
Keyword(s):  
Friction Force ◽  
Power Law ◽  
Early Stage ◽  
Nanocrystalline Diamond ◽  
The Self ◽  
Self Organization ◽  
Power Law Distribution ◽  
Reciprocating Sliding ◽  
Self Organized ◽  
Self Organized Criticality

The paper investigates the variation of friction force (Fx) during reciprocating sliding tests on nanocrystalline diamond (NCD) films. The analysis of the friction behavior during the run-in period is the focus of the study. The NCD films were grown using microwave plasma-enhanced chemical vapor deposition (MW-PECVD) on single-crystalline diamond SCD(110) substrates. Reciprocating sliding tests were conducted under 500 and 2000 g of normal load using Si3N4 balls as a counter body. The friction force permanently varies during the test, namely Fx value can locally increase or decrease in each cycle of sliding. The distribution of friction force drops (dFx) was extracted from the experimental data using a specially developed program. The analysis revealed a power-law distribution f-µ of dFx for the early stage of the run-in with the exponent value (µ) in the range from 0.6 to 2.9. In addition, the frequency power spectrum of Fx time series follows power-law distribution f-α with α value in the range of 1.0–2.0, with the highest values (1.6–2.0) for the initial stage of the run-in. No power-law distribution of dFx was found for the later stage of the run-in and the steady-state periods of sliding with the exception for periods where a relatively extended decrease of coefficient of friction (COF) was observed. The asperity interlocking leads to the stick-slip like sliding at the early stage of the run-in. This tribological behavior can be related to the self-organized criticality (SOC). The emergence of dissipative structures at the later stages of the run-in, namely the formation of ripples, carbonaceous tribolayer, etc., can be associated with the self-organization (SO).

scholarly journals Assessing, measuring and modelling erosion in calanchi areas: a review

2016 ◽  
Vol 47 (4) ◽  
pp. 181 ◽  
Author(s):  
Nathalie Almaru Caraballo-Arias ◽  
Vito Ferro
Keyword(s):  
Dimensional Analysis ◽  
Recent Literature ◽  
Similarity Theory ◽  
Rapid Development ◽  
The Self ◽  
Geometric Features ◽  
Self Similarity ◽  
Full Size ◽  
Space And Time ◽  
Geomorphic Processes

Calanchi are erosion landforms characterised by a heavily dissected terrain with steep, unvegetated slopes and channels with a dendritic pattern, which rapidly incise and extend headwards. Recent literature focusing on badland systems highlights their similarity with other larger fluvial landforms, stating that these behave as a full size laboratory, due to their rapid development in space and time and to the diversity of geomorphic processes involved. In this paper, a brief review of the most important results on badland research is firstly presented. Then, the morphometric similarity between calanchi and other erosion landforms is discussed. Finally, models quantitatively relating the volume of sediments eroded from calanchi landforms and a set of geometric features of their tributary areas, by exploiting the dimensional analysis and the self-similarity theory, are presented.

THE SCALE-FREE AND SMALL-WORLD PROPERTIES OF COMPLEX NETWORKS ON SIERPINSKI-TYPE HEXAGON

Fractals ◽  
2020 ◽  
Vol 28 (03) ◽  
pp. 2050054
Author(s):  
KUN CHENG ◽  
DIRONG CHEN ◽  
YUMEI XUE ◽  
QIAN ZHANG
Keyword(s):  
Power Law ◽  
Path Length ◽  
Small World ◽  
The Self ◽  
Renewal Theorem ◽  
Self Similarity ◽  
Scale Free ◽  
Power Law Exponent ◽  
Self Similar ◽  
Encoding Method

In this paper, a network is generated from a Sierpinski-type hexagon by applying the encoding method in fractal. The criterion of neighbor is established to quantify the relationships among the nodes in the network. Based on the self-similar structures, we verify the scale-free and small-world effects. The power-law exponent on degree distribution is derived to be [Formula: see text] and the average clustering coefficients are shown to be larger than [Formula: see text]. Moreover, we give the bounds of the average path length of our proposed network from the renewal theorem and self-similarity.

scholarly journals CAN AGN FEEDBACK BREAK THE SELF-SIMILARITY OF GALAXIES, GROUPS, AND CLUSTERS?

2014 ◽  
Vol 783 (1) ◽  
pp. L10 ◽  
Author(s):  
M. Gaspari ◽  
F. Brighenti ◽  
P. Temi ◽  
S. Ettori
Keyword(s):  
The Self ◽  
Self Similarity

scholarly journals Making the Grade during Pandemic: Early-stage and Late-stage Provisional Institutions

2021 ◽  
pp. 073112142110286
Author(s):  
Alexander B. Kinney ◽  
Nicholas J. Rowland
Keyword(s):  
Late Stage ◽  
Early Stage ◽  
State University ◽  
Institutional Work ◽  
Traditional Grading ◽  
Grading Policy ◽  
Temporary Solution ◽  
Rural State ◽  
Empirical Implications ◽  
Common Understanding

This is an article that draws on the institutional work literature about provisional institutions. To date, nearly every U.S. sector has been impacted by COVID-19. To sustain their core missions, highly institutionalized organizations such as universities have had to rethink foundational structures and policies. Using a historical ethnographic approach to investigate records from faculty senate deliberations at “Rural State University” (RSU), the authors examine the implementation of a temporary grading policy to supplement traditional, qualitative grades spring 2020 during the outbreak. The authors find that RSU implemented a temporary, supplemental grading policy as a provisional institution to momentarily supersede traditional grading as a means to—as soon as possible—return to it. This finding contrasts with the common understanding that provisional institutions operate primarily as a temporary solution to a social problem that leads to more stable and enduring, ostensibly nonprovisional institutions. The temporary grading policy, the authors argue, constitutes a “late-stage” provisional institution and, with this new lens, subsequently characterize the more commonplace understanding of provisional institutions as “early-stage.” This contribution has theoretical implications for studies of institutions and empirical implications for research on shared governance and disruption in higher education.

Health Insurance Status as a Predictor of Mode of Colon Cancer Detection but Not Stage at Diagnosis: Implications for Early Detection

2021 ◽  
pp. 003335492199917
Author(s):  
Lindsey A. Jones ◽  
Katherine C. Brewer ◽  
Leslie R. Carnahan ◽  
Jennifer A. Parsons ◽  
Blase N. Polite ◽  
...  
Keyword(s):  
Colon Cancer ◽  
Health Insurance ◽  
Early Detection ◽  
Late Stage ◽  
Early Stage ◽  
Insurance Status ◽  
Stage At Diagnosis ◽  
Health Insurance Status ◽  
Percentage Point Increase ◽  
Point Increase

Objective For colon cancer patients, one goal of health insurance is to improve access to screening that leads to early detection, early-stage diagnosis, and polyp removal, all of which results in easier treatment and better outcomes. We examined associations among health insurance status, mode of detection (screen detection vs symptomatic presentation), and stage at diagnosis (early vs late) in a diverse sample of patients recently diagnosed with colon cancer from the Chicago metropolitan area. Methods Data came from the Colon Cancer Patterns of Care in Chicago study of racial and socioeconomic disparities in colon cancer screening, diagnosis, and care. We collected data from the medical records of non-Hispanic Black and non-Hispanic White patients aged ≥50 and diagnosed with colon cancer from October 2010 through January 2014 (N = 348). We used logistic regression with marginal standardization to model associations between health insurance status and study outcomes. Results After adjusting for age, race, sex, and socioeconomic status, being continuously insured 5 years before diagnosis and through diagnosis was associated with a 20 (95% CI, 8-33) percentage-point increase in prevalence of screen detection. Screen detection in turn was associated with a 15 (95% CI, 3-27) percentage-point increase in early-stage diagnosis; however, nearly half (47%; n = 54) of the 114 screen-detected patients were still diagnosed at late stage (stage 3 or 4). Health insurance status was not associated with earlier stage at diagnosis. Conclusions For health insurance to effectively shift stage at diagnosis, stronger associations are needed between health insurance and screening-related detection; between screening-related detection and early stage at diagnosis; or both. Findings also highlight the need to better understand factors contributing to late-stage colon cancer diagnosis despite screen detection.

scholarly journals On the self-similarity of diffracting gaseous detonations and the critical channel width problem

2021 ◽  
Vol 33 (6) ◽  
pp. 066106
Author(s):  
M. I. Radulescu ◽  
R. Mével ◽  
Q. Xiao ◽  
S. Gallier
Keyword(s):  
The Self ◽  
Channel Width ◽  
Self Similarity ◽  
Gaseous Detonations

scholarly journals EU FP7 research funding for an orphan drug (Orfadin®) and vaccine (Hep C) development: a success and a failure?

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
L. Schmidt ◽  
O. Sehic ◽  
C. Wild
Keyword(s):  
Hepatitis C ◽  
Late Stage ◽  
Research Funding ◽  
Early Stage ◽  
Basic Research ◽  
Pharmaceutical Products ◽  
Clinical Development ◽  
Clinical Indication ◽  
Market Authorisation ◽  
Risk Capital

Abstract Background We considered the extent of the contribution of publicly funded research to the late-stage clinical development of pharmaceuticals and medicinal products, based on the European Commission (EC) FP7 research funding programme. Using two EC FP7-HEALTH case study examples—representing two types of outcomes—we then estimated wider public and charitable research funding contributions. Methods Using the publicly available database of FP7-HEALTH funded projects, we identified awards relating to late-stage clinical development according to the systematic application of inclusion and exclusion criteria, classified them according to product type and clinical indication, and calculated total EC funding amounts. We then identified two case studies representing extreme outcomes: failure to proceed with the product (hepatitis C vaccine) and successful market authorisation (Orfadin® for alkaptonuria). Total public and philanthropic research funding contributions to these products were then estimated using publicly available information on funding. Results 12.3% (120/977) of all EC FP7-HEALTH awards related to the funding of late-stage clinical research, totalling € 686,871,399. Pharmaceutical products and vaccines together accounted for 84% of these late-stage clinical development research awards and 70% of its funding. The hepatitis C vaccine received total European Community (FP7 and its predecessor, EC Framework VI) funding of €13,183,813; total public and charitable research funding for this product development was estimated at € 77,060,102. The industry sponsor does not consider further development of this product viable; this now represents public risk investment. FP7 funding for the late-stage development of Orfadin® for alkaptonuria was so important that the trials it funded formed the basis for market authorisation, but it is not clear whether the price of the treatment (over €20,000 per patient per year) adequately reflects the substantial public funding contribution. Conclusions Public and charitable research funding plays an essential role, not just in early stage basic research, but also in the late-stage clinical development of products prior to market authorisation. In addition, it provides risk capital for failed products. Within this context, we consider further discussions about a public return on investment and its reflection in pricing policies and decisions justified.

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