PIPCIRs-Polynomials Whose Inflection Points Coincide with Their Interior Roots

2000 ◽  
Vol 73 (4) ◽  
pp. 285
Author(s):  
Rachel Belinsky ◽  
Peter Andrews
Keyword(s):  
Inflection Points

Identifying Market Inflection Points

CFA Digest ◽  
2010 ◽  
Vol 40 (1) ◽  
Author(s):  
Russell Napier
Keyword(s):  
Inflection Points

A Novel Thyroid Ultrasound Proficiency Metric Designed Through a Multidisciplinary Delphi Approach

2021 ◽  
pp. 000313482110111
Author(s):  
Yinin Hu ◽  
Alex D. Michaels ◽  
Rachita Khot ◽  
Worthington G. Schenk ◽  
John B. Hanks ◽  
...  
Keyword(s):  
Learning Curves ◽  
Delphi Panel ◽  
Thyroid Ultrasound ◽  
Point Scale ◽  
Image Capture ◽  
Delphi Approach ◽  
Inflection Points ◽  
Operative Planning ◽  
Positioning Technique ◽  
Formally Trained

Background Thyroid ultrasounds extend surgeons’ outpatient capabilities and are essential for operative planning. However, most residents are not formally trained in thyroid ultrasound. The purpose of this study was to create a novel thyroid ultrasound proficiency metric through a collaborative Delphi approach. Methods Clinical faculty experienced in thyroid ultrasound participated on a Delphi panel to design the thyroid Ultrasound Proficiency Scale (UPS-Thyroid). Participants proposed items under the categories of Positioning, Technique, Image Capture, Measurement, and Interpretation. In subsequent rounds, participants voted to retain, revise, or exclude each item. The process continued until all items had greater than 70% consensus for retention. The UPS-Thyroid was pilot tested across 5 surgery residents with moderate ultrasound experience. Learning curves were assessed with cumulative sum. Results Three surgeons and 4 radiologists participated on the Delphi panel. Following 3 iterative Delphi rounds, the panel arrived at >70% consensus to retain 14 items without further revisions or additions. The metric included the following items on a 3-point scale for a maximum of 42 points: Positioning (1 item), Technique (4 items), Image Capture (2 items), Measurement (2 items), and Interpretation (5 items). A pilot group of 5 residents was scored against a proficiency threshold of 36 points. Learning curve inflection points were noted at between 4 to 7 repetitions. Conclusions A multidisciplinary Delphi approach generated consensus for a thyroid ultrasound proficiency metric (UPS-Thyroid). Among surgery residents with moderate ultrasound experience, basic proficiency at thyroid ultrasound is feasible within 10 repetitions.

scholarly journals How Many Inflections are There in the Lyapunov Spectrum?

2021 ◽  
Author(s):  
O. Jenkinson ◽  
M. Pollicott ◽  
P. Vytnova
Keyword(s):  
Piecewise Linear ◽  
Lyapunov Spectrum ◽  
Stat Phys ◽  
Linear Map ◽  
Piecewise Linear Map ◽  
Expanding Map ◽  
Lyapunov Spectra ◽  
Linear Maps ◽  
Inflection Points ◽  
Piecewise Linear Maps

AbstractIommi and Kiwi (J Stat Phys 135:535–546, 2009) showed that the Lyapunov spectrum of an expanding map need not be concave, and posed various problems concerning the possible number of inflection points. In this paper we answer a conjecture in Iommi and Kiwi (2009) by proving that the Lyapunov spectrum of a two branch piecewise linear map has at most two points of inflection. We then answer a question in Iommi and Kiwi (2009) by proving that there exist finite branch piecewise linear maps whose Lyapunov spectra have arbitrarily many points of inflection. This approach is used to exhibit a countable branch piecewise linear map whose Lyapunov spectrum has infinitely many points of inflection.

Collaborative Study of a Titrimetric Method for the Assay of Amitrole Formulations

1967 ◽  
Vol 50 (3) ◽  
pp. 568-572
Author(s):  
J Russell Bishop
Keyword(s):  
Collaborative Study ◽  
Statistical Analyses ◽  
Standard Samples ◽  
Titrimetric Method ◽  
Inflection Points ◽  
Good Agreement

Abstract titrimetric method for the assay of dry and liquid amitrole formulations was studied by 10 collaborators. In the method, acid is added to the prepared amitrole sample, the solution is titrated potentiometrically with standard alkali, and the amitrole content is measured as the amount of alkali consumed between the first and second inflection points. Collaborative results on standard samples of a dry 90% formulation, a dry 50% formulation, and a liquid 2 lb/gallon formulation showed good agreement between samples and laboratories. Statistical analyses of the results were satisfactory, and the method for the assay of amitrole formulations is recommended for adoption as official, first action

Detecting cusps and inflection points in curves

1992 ◽  
Vol 9 (1) ◽  
pp. 1-24 ◽  
Author(s):  
Dinesh Manocha ◽  
John F. Canny
Keyword(s):  
Inflection Points

scholarly journals Bayesian Metric Multidimensional Scaling

2013 ◽  
Vol 21 (1) ◽  
pp. 125-140 ◽  
Author(s):  
Ryan Bakker ◽  
Keith T. Poole
Keyword(s):  
Monte Carlo ◽  
Markov Chain ◽  
Bayesian Methods ◽  
Optimal Solution ◽  
Full Rank ◽  
Mcmc Methods ◽  
Ratio Scale ◽  
Posterior Distributions ◽  
Point Estimates ◽  
Inflection Points

In this article, we show how to apply Bayesian methods to noisy ratio scale distances for both the classical similarities problem as well as the unfolding problem. Bayesian methods produce essentially the same point estimates as the classical methods, but are superior in that they provide more accurate measures of uncertainty in the data. Identification is nontrivial for this class of problems because a configuration of points that reproduces the distances is identified only up to a choice of origin, angles of rotation, and sign flips on the dimensions. We prove that fixing the origin and rotation is sufficient to identify a configuration in the sense that the corresponding maxima/minima are inflection points with full-rank Hessians. However, an unavoidable result is multiple posterior distributions that are mirror images of one another. This poses a problem for Markov chain Monte Carlo (MCMC) methods. The approach we take is to find the optimal solution using standard optimizers. The configuration of points from the optimizers is then used to isolate a single Bayesian posterior that can then be easily analyzed with standard MCMC methods.

Inflection points in community-level homeless rates

2021 ◽  
Vol 15 (2) ◽  
Author(s):  
Chris Glynn ◽  
Thomas H. Byrne ◽  
Dennis P. Culhane
Keyword(s):  
Community Level ◽  
Inflection Points

scholarly journals Resistance behaviour of carbon fibre-reinforced polymers subjected to lightning strikes: Experimental investigation and application

2019 ◽  
Vol 28 ◽  
pp. 2633366X1989227 ◽  
Author(s):  
Jian Chen ◽  
Zhengcai Fu ◽  
Yang Zhao
Keyword(s):  
Carbon Fibre ◽  
Surface Resistance ◽  
Inflection Point ◽  
Front Surface ◽  
Resistance Change ◽  
Reinforced Polymers ◽  
Change Rate ◽  
Lightning Strikes ◽  
Inflection Points ◽  
Carbon Fibre Reinforced Polymers

It is difficult to monitor lightning damage to carbon fibre-reinforced polymers (CFRPs) online. This work experimentally investigates the changes associated with the electrical resistance of CFRPs subjected to lightning strikes. Two kinds of simulated lightning currents with different amplitudes in the range of 10–80 kA were injected into the CFRP samples. By measuring and comparing the changes in the struck-side (front) surface resistance, the surface resistance of the side opposite to the struck-side (back) and the oblique resistance of each sample before and after the lightning strike, it was observed that inflection points exist in the curve of the resistance change rate. The resistance decreases with increasing peak currents before the inflection point and increases when the peak current goes beyond the inflection point. The change rate of the front surface resistance is more sensitive to the lightning damage than are those of the back surface resistance and the oblique resistance. Different simulated lightning currents have approximately the same action integrals at the inflection points of resistance change rate. The characteristics indicate that resistance change detection could be a possible method for the online monitoring of CFRP lightning damage.

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